Technical Field
[0001] The present invention relates to a sliding plate, and particularly to a sliding plate
suitable for slidably supporting a tongue rail and to a self-lubrication type floor
plate for turnout, which uses the sliding plate.
Background Art
[0002] Patent Literature 1 discloses a floor plate for turnout (hereinafter, also referred
to as turnout floor plate), which can maintain sliding performance stably for a long
period of time, thereby allowing reduction in the frequency of maintenance and inspection
work. This turnout floor plate comprises: a substrate for placing and fixing a stock
rail on it; and a sliding plate, which is fixed on the substrate so that a tongue
rail is placed on the sliding plate and supported slidably.
[0003] The sliding plate comprises: a backing material, which is a steel plate having an
upper surface in which a plurality of recessed portions and projected portions are
formed; and a metal-powder sintered layer formed on the upper surface of the backing
material. The metal-powder sintered layer is formed on the upper surface of the backing
material as follows. Alloy powder for sintering is dispersed on the upper surface
of the backing material, and is sintered, and then is rolled. Thereafter, a lubricating
resin having superior weather resistance such aspolytetrafluoroethylene (PTFE), perfluoroalkoxyalkane
(PFA), polyamide-imide (PAI), polyimide (PI), or the like is heated and melted so
as to melt into the metal-powder sintered layer.
[0004] The metal-powder sintered layer formed on the projected portions of the upper surface
of the backing material is compressed under high pressure, and therefore has a higher
sintered density and is superior in impact resistance, load bearing, and abrasion
resistance. On the other hand, the metal-powder sintered layer formed on the recessed
portions of the backing material is compressed under lower pressure in comparison
with the metal-powder sintered layer on the projected portions, and therefore has
a lower sintered density and a higher impregnation rate of the lubricating resin,
and is superior in lubrication property.
Citation List
Patent Literature
[0005] Patent Literature 1: Japanese Unexamined Patent Application Laid-Open No.
Hei9-221701
Summary of Invention
Technical Problem
[0006] Usually the turnout floor plate described in Patent Literature 1 uses checkered steel
plate as the backing material of the sliding plate. Checkered steel plate is sold
as ready-made product by a plurality of manufacturers. However, ready-made checkered
steel plate is limited in the number of types of plate thickness. Thus, in many cases
of producing the sliding plate, it is difficult to procure checkered steel plate having
the thickness corresponding to the thickness of the sliding plate to produce, among
ready-made products of checkered steel plate. As a result, it is necessary to adjust
the thickness of the metal-powder sintered layer depending on the thickness of the
sliding plate to produce. Accordingly, it is necessary to change the sintering conditions,
rolling conditions, and the like for each thickness of the sliding plate to be produced,
and thus management of the thickness of the sliding plate becomes troublesome.
[0007] Further, since checkered steel plate is originally intended to be used for anti-slip
purpose in floor surface, passageway, stairway, and the like, only a few kinds of
checker patterns are available for ready-made checkered steel plate. Thus, in the
case where ready-made checkered steel plate is used for producing the sliding plate,
it is not possible to change flexibly the ratio between the portions of the high sintered
density (i.e. the portions superior in impact resistance, load bearing, and abrasion
resistance) and the portions of the low sintered density (i.e. the portions that are
higher in impregnation rate of the lubricating resin and thus superior in lubrication
property) in the metal-powder sintered layer formed on the checkered steel plate.
Thus, it is also difficult to adj ust the performance of the sliding plate, considering
which is more important the impact resistance, the load bearing and the abrasion resistance
or the lubrication property.
[0008] Although it is possible to solve the above problem by using custom-ordered checkered
steel plate of the desired sheet thickness and the desired checker pattern, this largely
increases the manufacturing cost.
[0009] The present invention has been made considering the above situation. An object of
the present invention is to provide a sliding plate whose thickness and performance
can be easily adjusted and a turnout floor plate, which uses this sliding plate.
Solution to Problem
[0010] To solve the above problems, for example in a sliding plate of the present invention,
a metal plate having mesh structure such as perforated metal, expanded metal, or a
metal plate with recessed portions and projected portions formed on its surface is
placed as a reinforced member on a backing material such as a steel plate; sintering
alloy powder is sprinkled on the backing material on which the reinforced member is
placed, and the backing material on which the reinforced member is placed and the
sintering alloy powder is sprinkled is sintered and rolled to form a metal-powder
sintered layer. Thereafter, the metal-powder sintered layer is impregnated with at
least one of a lubricating resin and lubricating oil.
[0011] For example, a sliding plate of the present invention comprises:
a backing material;
a reinforcing member, which is placed on one surface of the backing material and forms
recessed portions and projected portions in its surface; and
a metal-powder sintered layer, which is formed to cover at least the recessed portions
formed by the reinforcing member on the one surface of the backing material and is
impregnated with at least one of a lubricating resin and lubricating oil.
[0012] Further, a turnout floor plate of the present invention comprises:
a substrate for placing and fixing a stock rail on one surface of the substrate;
the above-mentioned sliding plate, which is fixed on the substrate and supports a
tongue rail slidably on a side of one surface of the substrate.
Advantageous Effects of Invention
[0013] According to the present invention, the metal-powder sintered layer, which covers
at least the recessed portions between the recessed portions and the projected portions
formed by the reinforcing member in the upper surface of the backing material, is
formed on the side of the upper surface of the backing material on which the reinforcing
member is placed. As for the metal-powder sintered layer formed on the projected portions
between the recessed portions and the projected portions, the metal-powder sintered
layer is compressed under high pressure, and thus has a higher sintered density and
is superior in impact resistance, load bearing, and abrasion resistance. On the other
hand, the metal-powder sintered layer formed on the recessed portions between the
recessed portions and the projected portions is compressed under lower pressure in
comparison with the metal-powder sintered layer formed on the projected portions.
Thus, the metal-powder sintered layer formed on the recessed portions has a lower
sintered density and a higher impregnation rate of at least one of the lubricating
resin and the lubricating oil, and is superior in lubrication property. As the backing
material, the present invention uses steel plate or the like, for which there are
ready-made products of more various plate thicknesses in comparison with checkered
steel plate, so that sliding plates of various thickness can be realized without changing
the thickness of the metal-powder sintered layer, making it easy to adjust the thickness
of the sliding plate. Further, according to the present invention, by using a metal
plate having mesh structure, such as perforated metal, expanded metal, or the like,
as the reinforcing member, the shapes and arrangement pattern of the holes of the
mesh can be changed easily. Accordingly, it is possible to change flexibly the ratio
between the high sintered density area and the low sintered density area of the metal-powder
sintered layer, making it easy to adjust the performance of the sliding plate.
Brief Description of Drawings
[0014]
Fig. 1(A) is a front view showing a turnout floor plate 1 according to one embodiment
of the present invention, and Fig. 1 (B) is a top view showing the turnout floor plate
1 according to the one embodiment of the present invention; and
Fig. 2(A) is a top view showing a sliding plate 3, and Fig. 2 (B) is an A-A cross-section
of the sliding plate 3 shown in Fig. 2(A).
Description of Embodiments
[0015] In the following, an embodiment of the present invention will be described referring
to the accompanying drawings.
[0016] Fig. 1(A) is a front view showing a turnout floor plate 1 according to the present
embodiment. And Fig. 1 (B) is a top view showing the turnout floor plate 1 according
to the present embodiment. In these figures, a stock rail 4, a tongue rail 5, and
a rail press 6 are shown in dotted lines so that disposition of these parts on the
turnout floor plate 1 can be easily grasped.
[0017] The turnout floor plate 1 of the present embodiment is used as a self-lubrication
type floor plate at a point where a turnout for railroad line is installed. As shown
in the figures, the turnout floor plate 1 of the present embodiment comprises: a substrate
2 for placing and fixing the stock rail 4 on one surface (i.e. upper surface) 20;
and a sliding plate 3, which is fixed on the upper surface 20 of the substrate 2 and
used for placing and supporting the tongue rail 5 slidably on the side of the upper
surface 20 of the substrate 2.
[0018] In the upper surface 20 of the substrate 2, are formed two parallel grooves (a stock
rail fixing groove 24 and a sliding plate fixing groove 25) running from one side
surface 22 to the other side surface 23 along to the lengthwise direction L. The stock
rail fixing groove 24 receives the base 41 of the stock rail 4. The sliding plate
fixing groove 25 accommodates the sliding plate 3 such that an upper surface 30 of
the sliding plate 3 is exposed in the upper surface 20 of the substrate 2.
[0019] Further, in the upper surface 20 of the substrate 2, a rail press fixing groove 26
is formed on the opposite side of the stock rail fixing groove 24 for the sliding
plate fixing groove 25. The rail press fixing groove 26 runs from the one side surface
22 of the substrate 2 to the other side surface 23, obliquely to the stock rail fixing
groove 24. In addition, in the substrate 2, is formed a bolt support hole 27 which
passes through the upper surface 20 of the substrate 2 and the other surface (i.e.
lower surface) 21 of the substrate 2. The stock rail 4 is placed on the bottom surface
242 of the stock rail fixing groove 24. The rail press 6 is in contact with the base
41 of the stock rail 4 on the side opposite to the side on which the tongue rail 5
is placed, for the stock rail 4. And a hook portion 61 of the rail press 6 is engaged
with the rail press fixing groove 26. In this state, when the rail press 6 slides
along the rail press fixing groove 26 in the direction D of narrowing the distance
between the rail press fixing groove 26 and the stock rail fixing groove 24, the rail
press 6 presses the base 41 of the stock rail 4 against one side surface 241 (the
side surface on the side of the sliding plate fixing groove 25) of the stock rail
fixing groove 24 by the wedge effect, while the rail press 6 supports the stem 42
of the stock rail 4 from the side opposite to the side onwhich the tongue rail 5 is
placed. This prevents a fall of the stock rail 4. When, in this state, the rail press
6 is bolted to the substrate 2 by using the bolt support hole 27, the stock rail 4
is fixed strongly to the substrate 2.
[0020] At each widthwise end portion 28 of the substrate 2, are formed a plurality of bolt
holes 29 each running through the upper surface 20 of the substrate 2 to the lower
surface 21 of the substrate 2, in order to fix the turnout floor plate 1 at the installation
point.
[0021] The sliding plate 3 has the length W2 narrower than the length W1 of the substrate
2. Accordingly, when the sliding plate 3 is accommodated in the sliding plate fixing
groove 25 of the substrate 2, the bottom surface 251 of the sliding plate fixing groove
25 is partly exposed on the sides of both the side surfaces 22 and 23 of the substrate
2. By using these exposed parts, the sliding plate 3 is fixed to the substrate 2 by
fillet welding.
[0022] Fig. 2(A) is a top view showing the sliding plate 3, and Fig. 2(B) is an A-A cross-section
of the sliding plate 3 shown in Fig. 2(A).
[0023] As shown in the figures, the sliding plate 3 has laminated structure. The sliding
plate 3 comprises: a backing material 31 made of, for example, steel plate; a perforated
metal 32 placed on the backing material 31; a metal-powder sintered layer 33 formed
on the side of the upper surface 310 of the backing material 31, to cover the perforated
metal 32.
[0024] As the backing material 31, is used metal plate available in many thicknesses t1
such as, for example, ready-made sheet steel. For example, SPHC (hot-rolled soft sheet
steel JIS G3131) can be mentioned as such sheet steel.
[0025] The perforated metal 32 is a metal plate having mesh structure made by punching a
metal plate by a dedicated punch press. The perforated metal 32 is satisfactorily
held on the backing material 31 when the metal-powder sintered layer 33 (which covers
at least the recessed portions between the recessed portions and projected portions
formed by placing the perforated metal 32 on the backing material 31) is joined to
the backing material 31. Fig. 2 shows an example of using the perforated metal 32
in which a plurality of diamond shapes are punched out into uniform arrangement. However,
shape, size, and arrangement pattern of the holes of the perforated metal 32 are not
limited to those shown in Fig. 2, as long as the perforated metal 32 has the aperture
ratio corresponding to the ratio between the high sintered density area (i.e. the
portions superior in impact resistance, load bearing, and abrasion resistance) and
the low sintered density area (i.e. the portions that are higher in impregnation rate
of the lubricating resin and thus superior in lubrication property) in the below-described
metal-powder sintered layer 33. For example, the holes may be circular, or the holes
of different sizes may be formed. Or, a plurality of holes may be arranged into areas
having different aperture ratios.
[0026] The metal-powder sintered layer 33 is formed by sintering of mixed powder obtained
by mixing sintering alloy powder with solid lubricant such as graphite, PTFE, molybdenum
disulfide (MoS
2) or the like. Here, for the mixed powder, may be used various materials, including
bronze type material containing copper, tin, a solid lubricant, and the like. Among
others, a mixed powder containing 4 - 10 wt. % tin, 10 - 40 wt. % nickel, 0.1 - 4
wt. % phosphorus, 3 - 10 wt. % graphite, and the balance copper can realize the metal-powder
sintered layer 33 giving the best sliding performance.
[0027] The metal-powder sintered layer 33 is impregnated with a lubricating resin superior
in weather resistance. Examples of such a lubricating resin are PTFE, PFA, PAI, PI,
PE (polyethylene), and PP (polypropylene). Also the lubricating resin may contain
dispersed solid lubricant such as graphite, PTFE, molybdenum disulfide, or the like.
[0028] The sliding plate 3 of the above-described structure is produced as follows. First,
the backing material 31 and the perforated metal 32 are each subjected to leveler
processing so that the backing material 31 and the perforated metal 32 are flattened.
Then, the perforated metal 32 is placed on the backing material 31; the above-described
mixed powder is sprinkled to a prescribed thickness on the side of the upper surface
310 of the perforated metal 32; and primary sintering is performed to form an intermediate
of the metal-powder sintered layer 33. Next, the backing material 31 provided with
the intermediate of the metal-powder sintered layer 33 and the perforated metal 32
is subjected to rolling. At that time, there is a possibility that a defect such as
a crack occurs in the intermediate of the metal-powder sintered layer 33. Therefore,
the intermediate of the metal-powder sintered layer 33 is further subjected to secondary
sintering to eliminate the defect such as crack. By this, a completed body of the
metal-powder sintered layer 33 is formed. The completed body of the metal-powder has
strength required to prevent a defect such as a crack due to external force at the
time of use, has joint strength required to strongly join the backing material 31
and the perforated metal 32 as a reinforcing member, and has hardness required to
good abrasion resistance. Next, the backing material 31 provided with the completed
body of the metal-powder sintered layer 33 and the perforated metal 32 is subjected
to rolling, and thereafter the completed body of the metal-powder sintered layer 33
is subjected to leveler processing to obtain the uniform thickness t2 of the completed
body of the metal-powder sintered layer 33. Then, the sliding plate 3 with desired
sliding performance is produced by heating and melting the above-mentioned lubricating
resin to impregnate the completed body of the metal-powder sintered layer 33 with
the lubricating resin.
[0029] Hereinabove, one embodiment of the present invention has been described.
[0030] According to the present embodiment, the metal-powder sintered layer 33 formed on
the metal part 321 of the perforated metal 32 is compressed under high pressure as
a result of the rolling and the leveler processing. Thus, the metal-powder sintered
layer 33 formed on this part has a higher sintered density and is superior in impact
resistance, load bearing, and abrasion resistance (the high sintered density area).
On the other hand, as a result of the rolling and the leveler processing, the metal-powder
sintered layer 33 formed in the holes (voids) 322 of the perforated metal 32 is compressed
under lower pressure in comparison with the metal-powder sintered layer 33 formed
on the metal part 321 of the perforated metal 32. Thus, the metal-powder sintered
layer 33 formed in this part has a lower sintered density and thus a higher impregnation
rate of the lubricating resin, and is accordingly superior in lubrication property
(the low sintered density area). Further, the metal-powder sintered layer 33 contains
the dispersed solid lubricant such as graphite. In this way, the metal-powder sintered
layer 33 is a mixture of the high sintered density area (which is superior in impact
resistance, load bearing, and abrasion resistance) and the low sintered density area
(which is superior in lubrication property). Accordingly, plastic deformation or the
like does not occur due to impact load applied to the tongue rail 5 at the time of
train passing, and the tongue rail 5 can be slidably supported stably over a long
period of time.
[0031] Here, in the present embodiment, as the backing material 31, it is possible to use
ready-made sheet steel available in more types of sheet thickness t1 in comparison
with checkered steel plate. Accordingly, as the backing material 31, it is possible
to use sheet steel whose thickness t1 corresponds to the thickness of the sliding
plate 3 to be produced, without changing the thickness t2 of the metal-powder sintered
layer 33. As a result, it is possible to realize the sliding plates 3 of various thicknesses
without changing manufacturing conditions such as sintering conditions, rolling conditions,
and the like. Thus, it is easy to adjust the thickness of the sliding plate 3.
[0032] Further, in the present embodiment, the perforated metal 32 placed on the backing
material 31 forms the high sintered density area and the low sintered density area
of the metal-powder sintered layer 33. By changing shapes, sizes, and arrangement
pattern of the holes (voids) 322 of the perforated metal 32, it is possible to change
flexibly the ratio between the high sintered density area and the low sintered density
area of the metal-powder sintered layer 33. Accordingly, it is easy to adjust the
performance of the sliding plate 3. For example, by preparing in advance a plurality
of types of perforated metal 32 which are different in shapes, sizes, and arrangement
patterns of the holes, it is possible to realize the sliding plate 3 of desired performance
only by changing the perforated metal 32 to one which has the aperture ratio corresponding
to the ratio between the high sintered density area and the low sintered density area
of the metal-powder sintered layer 33, while using the common backing material 31.
[0033] Further, according to the present embodiment, the performance of the sliding plate
3 can be adjusted also by changing the material of the perforated metal 32. For example,
by using sheet steel SS400 (rolled steel for general structure JIS G3101) or the like
as the material of the perforated metal 32, it is possible to produce the sliding
plate 3 emphasizing impact resistance, load bearing, and abrasion resistance. On the
other hand, by using bronze alloy type metal plate as the material of the perforated
metal 32, it is possible to produce the sliding plate 3 emphasizing lubrication property.
[0034] Thus, according to the present embodiment, it is possible to provide the sliding
plate 3 whose thickness and performance can be easily adjusted and to provide the
turnout floor plate 1 using that sliding plate 3.
[0035] Although, in the sliding plate 3 of the above-described embodiment, the whole area
is covered with the metal-powder sintered layer 33, the present invention is not limited
to this. It is sufficient that the metal-powder sintered layer 33 covers at least
a part of the perforated metal 32. For example, the surface of the metal part 321
of the perforated metal 32 may be exposed in a state of being flush with the surface
of the metal-powder sintered layer 33. By exposing the surface of the metal part 321
of the perforated metal 32 to be flush with the surface of the metal-powder sintered
layer 33, it is possible to produce the sliding plate 3 further emphasizing impact
resistances, load bearing, and abrasion resistance.
[0036] Further, in the sliding plate 3 of the above-described embodiment, the metal-powder
sintered layer 33 is impregnated with the lubricating resin. The metal-powder sintered
layer 33, however, may be impregnated with lubricating oil instead of the lubricating
resin or together with the lubricating resin.
[0037] Further, in the sliding plate 3 of the above-described embodiment, the perforated
metal 32 is placed on the backing material 31, and the mixed powder comprising the
sintering alloy powder and the solid lubricant is sprinkled onto the perforated metal
32 and then sintering and rolling are performed to form the metal-powder sintered
layer 33. The present invention, however, is not limited to this. The metal-powder
sintered layer 33 may be formed by: sprinkling sintering alloy powder without containing
solid lubricant onto the backing material 31; placing the perforated metal 32 on the
backing material 31 on which the sintering alloy powder has been sprinkled; and sprinkling
mixed powder comprising sintering alloy powder and solid lubricant onto the perforated
metal 32, and then performing sintering and rolling. This can increase the joint strengths
among the backing material 31, the perforated metal 32, and the metal-powder sintered
layer 33.
[0038] Further, in the sliding plate 3 of the above-described embodiment, the perforated
metal 32 is placed on the backing material 31. The present invention, however, is
not limited to this. It is sufficient for the present invention that a reinforcing
member allowing formation of recessed and projected portions on the side of the upper
surface 310 of the backing material 31 is placed on the backing material 31. For example,
instead of the perforated metal 32, a metal plate having other mesh structure, such
as expanded metal, may be used to form the high sintered density area and the low
sintered density area. Here, the expanded metal means a metal plate having solid mesh
structure of seamless mesh.
[0039] The shapes, sizes or arrangement patterns of the holes of the metal plate which has
the mesh structure and is placed on the backing material 31 may be changed depending
on locations on the backing material 31. Or, metal plates having respective types
of mesh structure different in shapes, sizes or arrangement patterns may be used at
different locations on the backing material 31 in order to change partially the ratio
between the high sintered density area and the low sintered density area of the metal-powder
sintered layer 33 according to the performance required for the sliding plate 3. By
this, it is possible to realize the sliding plate 3 which has different performances
at the portions of the sliding plate 3 according to the required performances for
those portions, for example, with the central portion emphasizing lubrication property
and with the edge portion emphasizing impact resistance, load bearing, and abrasion
resistance.
[0040] Further, as the reinforcing member which is placed on the backing material 31 and
forms the recessed portions and projected portions on the side of the upper surface
310 of the backing material 31, it is possible to use a metal plate with recessed
portions and projected portions formed in the surface of the metal plate (i.e. a metal
plate whose recessed portions are not penetrating through). In that case, it is possible
to increase the area of contact between the reinforcing member and the backing material
31 and the area of contact between the reinforcing member and the metal-powder sintered
layer 33. Thus, it is also possible to increase the respective joint strengths among
the backing material 31, the reinforcing member, and the metal-powder sintered layer
33, in comparison with the case of using a metal plate having mesh structure such
as perforated metal, expanded metal or the like as the reinforcing member. As a method
of joining the reinforcing member and the backing material 31, can be mentioned, for
example, a method of plating at least one of the reinforcing member and the backing
material 31 with metal (copper, nickel, tin, brass, or the like) to realize diffusion
joining, a method of joining by brazing, and a method of mechanical joining such as
by screwing.
[0041] Or, it is possible to plate at least one of the backing material 31 and the reinforcing
member with the same metal as metal used in the metal-powder sintered layer 33. This
can increase the joint strengths among the backing material 31, the reinforcing member,
and the metal-powder sintered layer 33. For example, in the case of using bronze type
sintering alloy powder for the metal-powder sintered layer 33, higher joint strength
can be obtained by plating with copper.
[0042] Further, the sliding plate 3 of the above-described embodiment uses the metal-powder
sintered layer 33 that contains the dispersed solid lubricant. However, it is not
necessary to disperse the solid lubricant, and it is possible to use the metal-powder
sintered layer consisting of sintering alloy powder only.
[0043] Further, the above embodiment has been described taking an example where the sliding
plate 1 is used for the turnout floor plate 1. However, the sliding plate 3 can be
used in various sliding applications such as a slide bearing.
Industrial Applicability
[0044] The sliding plate of the present invention can be used in various sliding applications
such as a turnout floor plate, a slide bearing, and the like.
Reference Signs List
[0045]
1: turnout floor plate; 2: substrate; 3: sliding plate; 4: stock rail; 5: tongue rail;
6: rail press; 20: upper surface of the substrate; 21: lower surface of the substrate;
22: one side surface of the substrate, extending in the lengthwise direction of the
substrate; 23: the other side surface of the substrate, extending in the lengthwise
direction of the substrate; 24: stock rail fixing groove; 25: sliding plate fixing
groove; 26: rail press fixing groove; 27: bolt support hole; 28: both end portions
of the substrate; 29: bolt holes; 30: upper surface of the sliding plate; 31: backing
material; 32: perforated metal; 33: metal-powder sintered layer; 41: base of the stock
rail; 42: stem of the stock rail; 61: hook portion of the rail press; 241: side surface
of the stock rail fixing groove; 242: bottom surface of the stock rail fixing groove;
251: bottom surface of the sliding plate fixing groove; 310: upper surface of the
backing material; 321: metal part of the perforated metal; and 322 : void of the perforated
metal.