Throttle valve assembly body

Abstract

 A throttle valve assembly body comprises a main valve body portion (ll) formed integrally a pair of intake air passages (l2a, l2b) therein and a throttle valve shaft (l4) having two throttle valves (l5a, l5b). Three through-hole portions (l3a, l3b, l3c) are formed through the main valve body portion (ll) so as to penetrate the throttle valve shaft (l4). Two end through-hole portions (l3a, l3b) support and fit freely rotatively the throttle valve shaft (l4). An intermediate through-hole portion (l3) has a larger diameter that of an outer diameter of the throttle valve shaft (l4). A clearance (c) is formed between the intermediate through-hole portion (l3c) and the throttle valve shaft (l4). The clearance (c) is set larger than a bending amount of the throttle valve shaft (l4). The clearance (c) is to be set more than 80µm. Friction and/or seizure can not cause at the intermediate through-hole portion (l3c) and the assurance of the smoothly turning of the throttle valve shaft (l4) can be attained.

Description

BACKGROUND OF THE INVENTION

( Field of the Invention )

[0001] The present invention relates to a throttle valve assembly body and, more particularly to a throttle valve assembly body comprising a main valve body portion having a pair of intake air passages each of which provides a throttle valve therein, respectively. The throttle valve assembly body of this kind is used widely in a fuel injection type gasoline internal combustion engine such as in an automobile.

( Description of the Prior Art )

[0002] Fig. 4 shows a cross-sectional view of one example of a twin type throttle valve assembly body of the fuel injection type gasoline internal combustion engine. The twin type throttle valve assembly body including a pair of main valve body portions have been known in Japanese Patent Laid-Open Publication No. 2l4654/l983.

[0003] The above conventional twin type throttle valve assembly body includes a pair of main valve body portions l0la and l0lb. A pair of throttle valve shafts l02a and l02b are arrayed at orthogonally through and supported rotatively within the respective main valve body portions l0la and l0lb. Each of throttle valve l03a or l03b is fixed on the throttle valve shaft l02a or l02b, respectively.

[0004] An accelerator lever ll4 is provided to the throttle valve shaft l02b and forced to give a turning force by a spring ll5 at a close-valve direction. Two stopper levers ll4a and ll4b are mounted on one end portion of the throttle valve shafts l02a and l02b, respectively.

[0005] An intermediate link l07 is connected to between the throttle valve shafts l02a and l02b and interlocks together the throttle valve shafts l02a and l02b. Thereby the throttle valve shaft l02a can be turn at the same turning degree that of the throttle valve shaft l02b, when another throttle valve shaft l02b is turned through the accelerator lever ll4.

[0006] The interlocking mechanism will be explained below in detail. The throttle valve shaft l02a or l02b forms respectively a male screw portion at a facing end portion to the throttle valve shaft l02b or l02a. Two levers l05 and ll2 are mounted on the respective male screw portions by nuts l06a and l06b. The nuts l06a and l06b form respectively ball bearing portions within themselves.

[0007] The intermediate link l07 forms integrally two ball members l07a and l07b at both end portions thereof. The ball members l07a and l07b are fitted respectively themselves into the ball bearing portions of the nuts l06a and l06b. Two levers l07c and l07d are mounted integrally on the intermediate portion of the intermediate link l07 and disposed to be opposite respectively to the lever l05 and the lever ll2.

[0008] The lever l05 and the lever l07c are fixed at a relative position by a setscrew ll0 and a check nut lll. The lever ll2 and the lever l07d are fixed at a relative position by suitably adjusting an adjustment screw l08. A spring l09 is disposed between the adjustment screw l08 and the lever ll2.

[0009] When the relationship position between the lever l07c and the lever ll2 is adjusted, however the lever l07d can be move any amount of range by squeezing the adjustment screw l08. Because of even though one stopper l04a of which the stoppers l04a and l04b contacts to the main valve body portion l0la, another stopper l04b parts from the main body portion l0lb.

[0010] As a result, the adjustment of an air amount during idling operation becomes difficult extremely. For the interlocking mechanism having the intermediate link l07 interlockes two throttle valve shafts l02a and l02b each other, therefore many constituting components may be necessity, and further the throttle valve assembly body may be become large and increase in weight.

[0011] For the dissolution of the above inconveniences, a throttle valve assembly body, in which two main valve body portions are combined to each other and formed integrally and further single throttle valve shaft penetrates through the combined main valve body portion, may be supposed. However, by the adaption of such a throttle valve assembly body, the throttle valve assembly body may be become small and light in weight and further require no adjustment operation such as the intermediate link member.

[0012] However, when single throttle valve shaft having two throttle valves thereon is disposed so as to be penetrated the combined main valve body portion, the throttle valve shaft may be supported at three through-hole portions of the combined main valve body portion, which are two end through-hole portions and a central through-hole portion.

[0013] If the throttle valve shaft bend, a locally strong pressure may be cause at a part of bearing portions or two end through-hole portions, therefore there is the possibility that the throttle valve shaft can not turn smoothly.

[0014] When the throttle valve shaft is prevented from turning smoothly, for example, even though the driver releases a force from the accelerator pedal, the inconveniences such as a check for operating the close-­valve direction of the throttle valve shaft by the spring will be brought.

SUMMARY OF THE INVENTION

[0015] An object of the present invention is to provide a throttle valve assembly body wherein a throttle valve shaft can be turn smoothly.

[0016] Another object of the present invention is to provide a throttle valve assembly body wherein a throttle valve shaft is not contact with an inner surface of a central through-hole portion of a main valve body portion.

[0017] Further object of the present invention is to provide a throttle valve assembly body wherein a number of the constituting components therefor can be decreased.

[0018] Still object of the present invention is to provide a throttle valve assembly body wherein a throttle valve assembly body can be made smaller and lighter in weight.

[0019] A throttle valve assembly body comprises a main valve body portion formed integrally a pair of intake air passages therein and a throttle valve shaft having two throttle valves at orthogonally to the pair of intake air passages. Two throttle valves are disposed respectively one of the intake air passages.

[0020] Three through-hole portions are formed through the main valve body portion so as to penetrate the throttle valve shaft. Two end through-hole portions of three through-hole portions support and fit freely rotatively the throttle valve shaft. An intermediate through-hole portion of three through-hole portions has a larger diameter that of an outer diameter of the throttle valve shaft. A clearance is formed between the intermediate through-hole portion and the throttle valve shaft. The clearance is set larger than a bending or deflection amount of the throttle valve shaft. The clearance is to be set more than 80µm. The throttle valve shaft may be supported at two end portions via bearing members and bearing pressure members.

[0021] According to the throttle valve assembly body of the present invention, the throttle valve shaft is supported on two end through-hole portions among of three through-­hole portions in which the throttle valve shaft penetrates through the main valve body portion and loosely fitted on the intermediate through-hole portion of three through-­hole portions. Thereby even though the throttle valve shaft bend, friction and/or seizure can not cause at the intermediate through-hole portion and the assurance of the smoothly turning of the throttle valve shaft can be attained.

[0022] According to the present invention, the throttle valve assembly body can be constituted smaller, lighter in weight and at low cost. The throttle valve shaft can be turned smoothly, and also the throttle valve assembly body has an excellent effect that there is no need for maintenance and inspection.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 

Fig. l shows a cross-sectional view of a throttle valve assembly body according to one embodiment of the present invention;

Fig. 2 shows an explanation view for setting a clearance
and also a relationship between measurement portions and bending amounts of the throttle valve shaft;

Fig. 3 shows a cross-sectional view of a throttle valve assembly body according to another embodiment of the present invention; and

Fig. 4 shows a cross-sectional view of prior art of a conventional twin type throttle valve assembly body.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Fig. l shows a cross-sectional view of a throttle valve assembly body according to one embodiment of the present invention. A main valve body portion ll of the throttle valve assembly body in a fuel injection type gasoline internal combustion engine such as in an automobile forms integrally and provides a pair of intake air passages l2a and l2b therein. The main valve body portion ll has three through-hole portions l3a, l3b and l3c therewith at same plan linear line.

[0025] Single throttle valve shaft l4 is disposed within the main valve body portion ll at orthogonally to the pair of intake air passages l2a and l2b through three through-hole portions l3a, l3b and l3c. The throttle valve shaft l4 provides two throttle valves l5a and ll5b thereon. The throttle valve l5a is disposed in the intake air passage l2a. While the throttle valve l5b is disposed in the intake air passage l2b. An accelerator lever l6 is provided to the throttle valve shaft l4 and forced to give a turning force by a spring l7 at a close-­valve direction.

[0026] Among of three through-hole portions l3a, l3b and l3c, two through-hole portions l3a and l3b which are positioned respectively at end portions and constitutes bearing portions of the throttle valve shaft l4 so that the throttle valve shaft l4 can be fitted freely rotatively at two end through-hole portions l3a and l3b. Besides, the central or intermediate through-hole portion l3c has larger diameter than an outer diameter of the throttle valve shaft l4 and constitutes a loose fit portion.

[0027] Therefore, a clearance c is formed between an outer surface of the throttle valve shaft l4 and an inner surface of the central through-hole portion l3c. The dimensions of the clearance c are set larger than a bending or deflection amount of the throttle valve shaft l4 which is a deflection amount deflected by receiving a bending force.

[0028] To put it concretely, the dimensions of the clearance c is set larger than the bending or deflection amount which correspondes an estimate maximum bending amount when the throttle valve shaft l4 would be received.

[0029] By this throttle valve assembly body, when the throttle valve shaft l4 is bent, the throttle valve shaft l4 is not contact with the inner surface of the central through-hole portion l3c, therefore the throttle valve shaft l4 is free from the prevention of the smoothly turning.

[0030] Fig. 2 shows an explanation view of one example for setting the dimensions of the clearance c. The throttle valve shaft l4 is made of the soft iron ( JIS S45C ) and is a l0 mm in the diameter.

[0031] Four measurement portions A, B, C and D are set on the throttle valve shaft l4. Such a measurement portions A, B, C and D are positioned at installation portions of two throttle valves l5a and l5b with the throttle valve shaft l4. The bending amounts of the throttle valve shaft l4 in the measurement portions A, B, C and D are shown as a curve Y in Fig. 2, when the throttle valve assembly body is subjected to under a negative pressure value at -650 mm Hg. The maximum bending amount of the throttle valve shaft l4 in this case is about 80µm. The dimensions of the clearance c must be set larger than that of this maximum value, namely more than 80µm.

[0032] Fig. 3 shows different second embodiment of the present invention. The difference between the second embodiment and the first embodiment is constituting components for supporting the throttle valve shaft l4. The throttle valve shaft l4 in the second embodiment is supported at two end through-hole portions l3a and l3b thereof via bearing members 2la and 2lb. The clearance c is formed between the inner surface of the central or intermediate through-hole portion l3c and the outer surface of the throttle valve shaft l4 and constitutes a loose fit portion as same as the first embodiment. The bearing members 2la and 2lb are hold by bearing pressure members 22a and 22b, respectively.

[0033] Although by this throttle valve assembly body, when the throttle valve shaft l4 is bent, the throttle valve shaft l4 is not contact with the inner surface of the central through-hole portion l3c, therefore the throttle valve shaft l4 is free from the prevention of the smoothly turning.

[0034] In both the first and the second embodiments, the throttle valve assembly body is made smaller so as to constitute the integral component structure of the main valve body portion. The throttle valve assembly body structure becomes to be simple and also cut down the manufacturing cost thereof, because of no intermediate link member and no attaching members thereof. Further it is not necessary to provide the intermediate link member therein.

Claims

1. A throttle valve assembly body comprising;
a main valve body portion (ll) formed integrally a pair of intake air passages (l2a, l2b) therein, a throttle valve shaft (l4) having two throttle valves (l5a, l5b) disposed through said main valve body portion (ll) at orthogonally to the pair of intake air passages (l2a, l2b), and said throttle valves (l5a, l5b) disposed respectively one of the intake air passages (l2a, l2b) characterized in that
three through-hole portions (l3a, l3b, l3c) are formed through said main valve body portion (ll) so as to penetrate said throttle valve shaft (l4), two end through-­hole portions (l3a, l3b) of said three through-hole portions (l3a, l3b, l3c) support and fit freely rotatively said throttle valve shaft (l4), an intermediate through-­hole portion (l3c) of said three through-hole portions (l3a, l3b, l3c) has a larger diameter that of an outer diameter of said throttle valve shaft (l4), and a clearance (c) is formed between said intermediate through-­hole portion (l3c) and said throttle valve shaft (l4).

2. A throttle valve assembly body according to claim l, characterized in that said clearance (c) is set larger than a bending amount of said throttle valve shaft (l4).

3. A throttle valve assembly body according to claim l, characterized in that said clearance (c) is to be set more than 80µm.

4. A throttle valve assembly body comprising;
a main valve body portion (ll) formed integrally a pair of intake air passages (l2a, l2b) therein, a throttle valve shaft (l4) having two throttle valves (l5a, l5b) disposed through said main valve body portion (ll) at orthogonally to the pair of intake air passages (l2a, l2b), and said throttle valves (l5a, l5b) disposed respectively one of the intake air passages (l2a, l2b) characterized in that
three through-hole portions (l3a, l3b, l3c) are formed through said main valve body portion (ll) so as to penetrate said throttle valve shaft (l4) at two end portions via bearing members (2la, 2lb) and bearing pressure members (22a, 22b), two end through-hole portions (l3a, l3b) of said three through-hole portions (l3a, l3b, l3c) support and fit freely rotatively said throttle valve shaft (l4), an intermediate through-hole portion (l3c) of said three through-hole portions (l3a, l3b, l3c) has a larger diameter that of an outer diameter of said throttle valve shaft (l4), and a clearance (c) is formed between said intermediate through-hole portion (l3c) and said throttle valve shaft (l4).

5. A throttle valve assembly body according to claim 4, characterized in that said clearance (c) is set larger than a bending amount of said throttle valve shaft (l4).

6. A throttle valve assembly body according to claim 4, characterized in that said clearance (c) is to be set more than 80µm.

Drawing