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(11) | EP 0 743 383 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Loom drive mechanism |
| (57) In a loom drive mechanism capable of driving a shedding motion K which is a dobby
or a jacquard machine and a loom main body L without the shedding motion K in synchronism
with each other by a simple arrangement without increasing the size of a drive system
of the loom main body L and without the need of electrically synchronous drive control,
the loom drive mechanism comprises a main motor M1 for driving the loom main body
L, an auxiliary motor M2 for driving the shedding motion K and a coupling system C
for interlocking the drive shaft of the loom main body L with the drive shaft of the
shedding motion K by mechanical coupling. The auxiliary motor M2 shares a portion
of a shedding load required by the shedding motion K and a deficient load is imposed
on the main motor M1 through the coupling system C. |
BACKGROUND OF THE INVENTION
(Field of the Invention)
[0001] The present invention relates to a loom drive mechanism effectively applicable to a loom with a shedding motion which is a dobby or a jacquard machine.
(Description of the Related Art)
[0002] A dobby or a jacquard machine is a shedding motion which is separately disposed to a loom and can realize any arbitrary complex woven structure by shedding a warp to a predetermined shedding pattern through heald frame or wire heald in accordance with the operation of a loom.
[0003] Since the operation speed of the separately disposed shedding motion (hereinafter, simply referred to as a shedding motion) must be synchronized with that of a loom main body, that is, a loom without the shedding motion, it is usually driven by a drive motor for driving the loom main body through a coupling shaft or a transmission chain.
[0004] On the other hand, since a mechanical coupling system must transmit all the load (hereinafter, referred to as a shedding load) imposed on the shedding motion, the coupling system is not only increased in its mechanical size but also liable to generate vibration, noise and the like and the maintenance and check thereof are difficult. To cope with this problem, there is proposed an idea that independent drive motors are provided with a loom main body and a shedding motion, respectively to thereby drive them in an electrically synchronized state (for example, Japanese Patent Application Laid-Open No. HEI 3-249233, Japanese Utility Model Application Laid-Open No. HEI 4-89579). Note, the shedding motion often has a shedding load which appears as a variable load having an acute peak depending upon a woven structure.
[0005] The former of the aforesaid prior art has a problem that the size of the drive motor and the coupling system of the loom is enlarged and excessive vibration and noise are liable to be generated as well as the operation speed of the loom is varied due to the variation of the shedding load, thus weft insertion falls into disorder.
[0006] Further, the latter of the above prior art has a problem that since a phase is delayed due to the variable shedding load imposed on the shedding motion, weft insertion falls into disorder, and to avoid this problem, a motor having a large capacity which greatly exceeds a substantially required capacity must be used as the drive motor of the shedding motion as well as a special servo motor which can effect a synchronous operation or the like must be used, by which the system is made every expensive as a whole.
OBJECT AND SUMMARY OF THE INVENTION
[0007] Taking the above problems of the prior art into consideration, a major object of the present invention is to provide a loom drive mechanism which can suppress an overall cost to a low level by employing such an arrangement that a loom main body having a main motor is coupled with a shedding motion having an auxiliary motor through a small and simple coupling system without the need of using a special servo motor having a large capacity or the like.
[0008] A gist of the arrangement of the present invention for achieving the above objects comprises a main motor for driving a loom main body, an auxiliary motor for driving a shedding motion, and an interlock means for interlocking the drive shaft of the loom main body with the drive shaft of the shedding motion by mechanical coupling.
[0010] In addition, the auxiliary motor can variably control the output torque through a torque controller in correspondence to a shedding load of the shedding motion and further generate output torque in coincidence with the shedding load of the shedding motion.
[0011] Note, the torque controller may variably control the output torque of the auxiliary motor in response to a shedding load signal output from a shedding load calculation means for calculating the shedding load of the shedding motion.
[0012] When the present invention is arranged as described above, since the mechanical coupling system mechanically interlocks a drive shaft of the loom main body with the drive shaft of the shedding motion to thereby maintain a synchronizing relationship therebetween, an electrically synchronizing device need not be interposed between the main motor and the auxiliary motor. Therefore, the auxiliary motor to be directly coupled with the shedding motion may be any motor so long as it assists the main motor and a special servo motor or the like need not be used. Further, it is sufficient for the mechanical coupling system only to interlock the loom main body having the main motor with the shedding motion having the auxiliary motor and maintain synchronous operation therebetween. Thus, since the mechanical coupling system need not transmit all the shedding load required by the shedding motion, it can be arranged as a simple element of small size. Note, the coupling system in this case may be any of a coupling shaft and a transmission chain.
[0013] When the auxiliary motor is arranged to generate the constant output torque, it shares a portion of the shedding load which corresponds to its output torque and a deficient shedding load is shared by the main motor through the mechanical coupling system.
[0014] When the output torque of the auxiliary motor is variably controlled in correspondence to the shedding load, the main motor need not share a variable portion of the shedding load and it suffices for the main motor only to share a given amount of a deficient shedding load. Therefore, the main motor can easily maintain the operating speed of the loom main body constant, thus it is possible to minimize troubles in weft insertion and the like which are caused by the variation of the operation speed of the loom main body.
[0015] When the auxiliary motor is arranged to generate output torque in coincidence with the shedding load, the auxiliary motor can share all the shedding load, thus it is sufficient for the coupling system which couples the drive shaft of the loom main body with the drive shaft of the shedding motion only to contribute to maintain synchronous operation therebetween. That is, the coupling system need not transmit even a portion of the shedding load, so that the occurrence of mechanical troubles based on the twist of the coupling shaft, the elongation of a transmission chain, and the like can be minimized.
[0016] When the shedding load signal from the shedding load calculation means is used to determine output torque of the auxiliary motor, the torque controller can easily cause the output torque of the auxiliary motor to correspond to the shedding load or to coincide it with the shedding load. This is because that shedding load calculation means can calculate the shedding load at real time and outputs it as the shedding load signal by utilizing, for example, a shedding signal for operating the shedding motion in accordance with a set shedding pattern.
[0017] As described above, according to the present invention, the synchronous relationship between the operation speed of the loom main body and the operation speed of the shedding motion can be maintained through the interlock means by the combination of the main motor for driving the loom main body, the auxiliary motor for driving the shedding motion and the interlock means for interlocking the shaft of the loom main body with the shaft of the shedding motion by mechanical coupling, and the auxiliary motor can assist the main motor. As a result, since the interlock means can be arranged as a simple element of small size as well as the auxiliary motor need not be driven in electrical synchronism with the main motor, there is an excellent advantage that a special servo motor or the like of large capacity need not be used all, thus an amount of harmful noise and vibration can be reduced and an overall cost can be suppressed to a low level.
[0018] The above and other objects, features and advantages of the present invention will become apparent from the following description when read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019]
FIG. 1 is a block diagram showing an entire arrangement according to an embodiment of the present invention;
FIG. 2 is a time chart explaining operation of the embodiment;
FIG. 3 is a block diagram equivalent to FIG. 1 explaining another embodiment of the present invention; and
FIG. 4 is a time chart equivalent to FIG. 2 explaining operation of the another embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] In FIG. 1, a loom drive mechanism includes a main motor M1 for driving a loom main body L, an auxiliary motor M2 for driving a shedding motion K and a coupling system C as an interlock means for mechanically coupling the drive shaft of the loom main body L with the drive shaft of the shedding motion K. Note, the shedding motion K is a separately disposed shedding motion such as a dobby or a jacquard machine which can realize a predetermined woven structure by driving not shown heald frames or wire healds mounted on the loom main body L in accordance with a predetermined shedding pattern.
[0021] The main motor M1 is not only coupled with the loom main body L but also with the shedding motion K through the coupling system C composed of gearing C1, a coupling shaft C2 and gearing C3. Note, the coupling system C may use a transmission chain in place of the coupling shaft C2. The auxiliary motor M2 is directly coupled with the shedding motion K.
[0022] The rotation of the main motor M1 is controlled through a motor controller 11. Note, the main motor M1 is an ordinary drive motor including an induction motor and the motor controller 11 may be, for example, an inverter device for controlling the loom main body L to the arbitrary operation speed n1 through the main motor M1.
[0023] The auxiliary motor M2 is a torque motor which exhibits dropping characteristics in its output torque. The auxiliary motor M2 is controlled by a torque controller 21 which is provided with a setting unit 21a for setting torque QS. The auxiliary motor M2 can apply a constant output torque
to the shedding motion K regardless of the operation speed n2 of the shedding motion K driven by the main motor M1. Note, the operation speed n2 of the shedding motion K is generally set to
through the coupling system C with respect to the operation speed n1 of the loom main body L.
[0024] When the shedding movement P of the heald frames or the wire healds effected by the shedding motion K is proceeds as shown in FIG. 2 with respect to a time t, the half cycle of the shedding movement P TP/2 corresponds to one cycle of the loom main body L. That is, a series of weaving movement effected by the loom main body L is repeated each half cycle TP/2 of the shedding movement P.
[0025] On the other hand, in the shedding movement P of the shedding motion K, since the heald frames or wire healds to be moved upward and downward each one cycle of the loom main body L according to a predetermined shedding pattern are designated in order to realize a predetermined woven structure, a shedding load Q of the shedding motion K varies each half cycle TP/2 of the shedding movement P and is not constant. Thus, when it is supposed that the auxiliary motor M2 generates the constant output torque
, the main motor M1 must share a deficient torque
. That is, The auxiliary motor M2 assists the main motor M1 and thus it is sufficient for the coupling system C only to transmit
of the shedding load Q.
[0026] FIG. 3 is a block diagram showing another embodiment of the present invention, wherein a shedding load signal Sq output from a shedding load calculation means 22 is input to a torque controller 21 for controlling an auxiliary motor M2.
[0027] A shedding signal Sk output from a shedding controller 23 is input to the shedding load calculation means 22 and the shedding signal Sk is also input to a shedding motion K. Note, forward and backward stepping signals St1, St2 are input from a not shown timing signal generator to the shedding controller 23 as well as a shedding pattern setting means 23b is connected to the shedding controller 23 through a memory means 23a.
[0028] The shedding pattern setting means 23b can set a shedding pattern Pk for realizing a predetermined woven structure and store it to the memory means 23a. On the other hand, when a loom main body L and the shedding motion K are driven in a forward direction, respectively by operating a main motor M1 and the auxiliary motor M2, the forward stepping signal St1 is input to the shedding controller 23 each time the drive shaft of the loom main body L rotates once. Then, the shedding controller 23 can read the shedding pattern Pk from the memory means 23a each one step in response to the stepping signal St1 and create a shedding signal Sk in accordance with the shedding pattern Pk.
[0029] The shedding motion K can realize the predetermined woven structure by receiving the shedding signal Sk output from the shedding controller 23 and driving the heald frames or wire healds as indicated by the shedding signal Sk. On the other hand, the shedding load calculation means 22 receives the shedding signal Sk and compares it with the shedding signal Sk at the previous step, so that the shedding load calculation means 22 can calculate a shedding load Q needed by the shedding motion K by finding, for example, the number of the heald frames or wire healds to be driven and the direction in which they move. This is because that an amount of a work required in shedding by the heald frames or wire healds to be driven by the shedding motion K is given for each moving direction thereof depending upon a type and operating conditions of the shedding motion K.
[0030] Note, the type of the shedding motion K includes such a type as a positive dobby, negative dobby, jacquard or the like and the operating conditions include the number of the heald frames and wire healds, tension of warp, an amount of shedding, spring back force for the negative dobby and jacquard, and the like. Note, the shedding load calculation means 22 may previously store shedding loads Q at respective steps measured actually in test weaving and successively read out them in response to the shedding signal Sk or the stepping signal St1 in place of calculating the shedding load Q using the above parameters.
[0031] The shedding load calculation means 22 outputs the shedding load Q calculated as described above to the torque controller 21 as a shedding load signal Sq. Thus, the torque controller 21 can variably control an output torque Q2 from the auxiliary motor M2 in correspondence to the shedding load Q as shown in FIG. 4. That is, the output torque Q2 at the time is smaller than the shedding load Q by a given deficient torque Q1, thus it is sufficient for the main motor M1 only to share the deficient torque Q1 through a coupling system C. Therefore, the coupling system C is required only to transmit the given torque Q1 with respect to a time t, so that there is no possibility that harmful twist and the like are caused. Further, since the main motor M1 need not share a variable portion of the shedding load Q, the operation speed of the loom main body L can be maintained constant and the variation thereof can be minimized.
[0032] Note, the output torque Q2 of the auxiliary motor M2 may be caused to coincide with the shedding load Q, that is,
so that
is achieved in the above embodiment. This is because that since the torque controller 21 variably controls the output torque Q2 of the auxiliary motor M2 based on the shedding load signal Sq output from the shedding load calculation means 22 in this case,
can be set by suitably adjusting the internal gain of the shedding load calculation means 22 or the torque controller 21. Note, since the coupling system C mechanically couples the drive shaft of the loom main body L with the drive shaft of the shedding motion K and contributes only to maintain synchronous operation therebetween, it need not transmit power for driving the shedding motion K.
[0033] In the above embodiment, the auxiliary motor M2 may be any type of a motor so long as it stably generates arbitrary torque Q2 regardless of the operation speed n2 of the shedding motion K by being combined with the torque controller 21, in addition to an ordinary torque motor.
[0034] Further, the shedding load calculation means 22 can include calculation for various types of mechanical losses generated by the shedding motion K in the shedding load Q. The mechanical losses can be more accurately calculated when they are corrected using parameters such as the operation speed n1 or n2 of the loom main body L or the shedding motion K, the oil temperature of the gear box included in the shedding motion K, the temperatures of bearings, and the like. Note, in this case, values corresponding to these parameters as the mechanical losses may be previously stored and then read out and used in accordance with the parameters.
[0035] In a loom drive mechanism capable of driving a shedding motion K which is a dobby or a jacquard machine and a loom main body L without the shedding motion K in synchronism with each other by a simple arrangement without increasing the size of a drive system of the loom main body L and without the need of electrically synchronous drive control, the loom drive mechanism comprises a main motor M1 for driving the loom main body L, an auxiliary motor M2 for driving the shedding motion K and a coupling system C for interlocking the drive shaft of the loom main body L with the drive shaft of the shedding motion K by mechanical coupling. The auxiliary motor M2 shares a portion of a shedding load required by the shedding motion K and a deficient load is imposed on the main motor M1 through the coupling system C.
1. A loom drive mechanism, comprising:
a main motor for driving a loom main body;
an auxiliary motor for driving a shedding motion; and
interlock means for interlocking the drive shaft of said loom main body with the drive shaft of said shedding motion by mechanical coupling.
2. A loom drive mechanism according to claim 1, wherein said auxiliary motor is arranged
to be able to generate a constant output torque.
3. A loom drive mechanism according to claim 1, wherein said auxiliary motor includes
a torque controller for variably controlling the output torque in correspondence to
a shedding load of said shedding motion.
4. A loom drive mechanism according to claim 3, wherein said auxiliary motor is arranged
to generate output torque which is in coincidence with the shedding load of said shedding
motion.
5. A loom drive mechanism according to claim 3 or claim 4, wherein said torque controller
is arranged to variably control the output torque of said auxiliary motor in response
to a shedding load signal output from shedding load calculation means for calculating
the shedding load of said shedding motion.
6. A loom drive mechanism according to claim 1, wherein said shedding motion is composed
of a dobby device or a jacquard machine.