JPH0430349Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Field of Application> The present invention relates to a torque spring device for an engine governor, and is intended to enable accurate adjustment of the torque spring.

<Prior Art> Conventionally, some governors used for engine speed control include a torque spring device in order to speed up the recovery of engine speed when the engine speed decreases. For example, as shown in FIG. 2, a floating lever 4 is provided in addition to the fork lever 3 that is engaged with the rack pin (or rack) 2 of the combustion injection pump 1, and the governor force GF is made to act directly on the fork lever 3. On the other hand, there is one in which the tension of the governor spring 5 is applied to the fork lever 3 via a floating lever 4 and a torque spring device 6 interposed between the floating and fork levers 3 and 4. This torque spring device 6 usually has a cylindrical holder 7 integrally cast on one of the fork lever 3 and the floating lever 4 (in this case, the fork lever 3) and has an end wall 7a on the other lever side. As shown in FIG. 4, a pin hole 8 having a smaller diameter than the inner diameter of the holder 7 is passed through the end wall 7a of the holder 7, so that the pin 9 can be moved back and forth into the holder 7.
and inserting the pin 9 so that one end 9a of the pin 9 moves out of the holder 7 through the pin hole 8,
A torque adjustment screw 10 is screwed into the opening 7b of the holder 7 so as to face the other end 9b of the pin 9, and a torque spring 11 made of a compression spring is interposed between the pin 9 and the torque adjustment screw 10. It is composed of

<Problems to be solved by the invention> In the conventional governor torque spring device configured as described above, the torque spring 11 and the torque adjustment screw 10 are in direct contact with each other, so that it is necessary to adjust the contact load described below. When tightening or loosening the torque adjustment screw 10, one end of the torque spring 11 rotates as the end surface of the torque adjustment screw 10 rotates, and the torque spring 11
is given a twist. After adjustment, such twisting of the torque spring 11 is gradually eliminated by vibrations during engine operation. However, the torque spring 11 and the torque adjustment screw 10
There are variations in torque spring eccentricity, machining dimensional errors, friction coefficient, etc. in the contact state with the torque spring 11, and the magnitude of the torsion that occurs becomes uneven. When the torsion is eliminated, there will be large variations in the contact loads between the torque spring devices 6 that were adjusted to the same contact load during adjustment. In addition, since the end surface of the torque adjustment screw 10 is formed into a substantially flat shape, the torque spring 11 is not settled properly, and the center of one end of the torque spring 11 is offset and formed on the inner circumferential surface of the opening 7b of the holder 7. The load is adjusted while the torque spring 11 is compressed more than the adjustment position.
Problems such as a decrease in the load of the torque spring 11 are also likely to occur when the hook is later released due to vibrations during driving or the like. Furthermore, due to vibrations during operation after adjustment, the end surfaces of the torque spring 11 and the torque adjustment screw 10 repeatedly hit each other, but the torque adjustment screw 10, which is made of a softer material than the torque spring, wears out. This may cause the spring load to decrease.

The present invention has been developed in consideration of the above circumstances, and allows for easy and accurate adjustment of the contact load of the torque spring device, and also prevents changes in the contact load during operation after adjustment. It is an object of the present invention to provide a torque spring device for an engine governor configured as described above.

<Means for Solving the Problems> In order to achieve the above object, in the engine governor torque spring device according to the present invention, a pin hole with a smaller diameter than the inner diameter of the holder is formed in the end wall of the cylindrical holder. The pin is inserted through the holder so that it can move forward and backward into the holder, and one end of the pin moves out of the holder through the pin hole, and the torque is adjusted by facing the other end of the pin. In a torque spring device for an engine governor, in which a screw is screwed into the opening of the holder, and a torque spring made of a compression spring is interposed between the pin and the torque adjustment screw, a torque spring is inserted between the torque adjustment screw and the torque spring. A spherical body is inserted into the torque adjusting screw, and a recess is formed in the torque adjusting screw to rotatably hold the spherical body on the axis of the torque adjusting screw.

In order to receive the torque spring, the sphere used has a diameter that is at least larger than the inner diameter of the torque spring. Also, the material of the sphere is
The material is not particularly limited as long as it has the necessary mechanical strength. However, from the viewpoint of preventing deformation of the torque adjustment screw due to impact force and prevention of wear, it is preferable to use a material having a hardness between that of the torque spring and the torque adjustment screw.

The recess formed in the torque adjustment screw is formed in the shape of a polygonal pyramid such as a triangular pyramid or a square pyramid, a polygonal truncated pyramid such as a truncated triangular pyramid or a truncated quadrangular pyramid, or a polygonal cylinder such as a triangular cylinder or a square cylinder. However, from the viewpoint of reducing the deformation and wear of the torque adjustment screw by increasing the contact area with the sphere and reducing the contact surface pressure, it is possible to use partially spherical, conical, truncated conical, and cylindrical shapes. It is preferable to form it into the shape of a rotating body, and most preferably to form it into a partial spherical shape that makes surface contact with the spherical body on its entire surface.

<Operation> According to the present invention configured as described above, the pressing force applied to the sphere by the torque spring can be received and dispersed by the recess formed in the torque adjustment screw, thereby reducing local stress on the inner surface of the recess and the surface of the sphere. concentration does not occur. As a result, when tightening or loosening the torque adjustment screw, slippage occurs between the torque adjustment screw and the sphere, so the end of the torque spring does not rotate with the torque adjustment screw.
Therefore, twisting of the torque spring does not occur. As a result, there is no risk of problems such as the torque spring being untwisted due to vibrations during operation and changing the contact load, and there is also no risk of variation in the contact load due to such changes in the contact load. . In addition, since the end of the torque spring is held on the axis of the torque adjustment screw through the sphere, there is no risk of the end of the torque spring getting caught in the thread groove on the inner circumferential surface of the holder. There is also no risk that the adhesive load will change due to loosening during operation.

<Example> An example of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is a cross-sectional plan view of an embodiment of the present invention, FIG. 2 is a side view of a governor equipped with a torque spring device according to an embodiment of the present invention, and FIG.
The figure is an explanatory diagram showing the procedure for adjusting the contact load according to an embodiment of the present invention.

The governor shown in FIG. 2 includes a fork lever 3 that is engaged with a rack pin 2 of a fuel injection pump 1;
It has a floating lever 4. These fork levers 3 and floating levers 4 are swingably supported on one side of the outer side of a cylinder block 13 of the engine via a common pivot shaft 12. A U-shaped engagement groove 14 into which the rack pin 2 is engaged is formed at one end of the fork lever 3, and the other end is brought into contact with one end surface 16a of a thruster sleeve 16 via a roller 15. The other end surface 16b of the thruster sleeve 16 is configured to receive the output arm 17a of the governor weight 17. The governor weight 17 is swingably supported via a weight holder 19 on a rotating shaft 18 that is interlocked with a crankshaft (not shown).
When the weight holder 8 and the weight holder 19 rotate, the weight part 17b is swung away from the center of the rotating shaft 18 by its own centrifugal force, and is transferred to the fork lever 3 via the output arm 17a and the thruster sleeve 16 in the direction of fuel reduction. It is configured to act on the governor force GF, which is driven in the counterclockwise direction in FIG. 2. On the other hand, the speed setting lever 20 and the floating lever 4
A governor spring 5 is mounted over the entire fuel tank, and the tension of the governor spring 5 is configured to bias the fork lever 3 in the fuel increasing direction via the floating lever 4 and the torque spring device 6.

The fork lever 3 is biased to the starting fuel increasing position by a start spring 21 when the engine is started, and a spring restricts the movement of the fork lever 3 to the fuel decreasing side when a sudden increase in rotation occurs. 22 to prevent engine stalling due to rapid fuel loss.

This torque spring device 6 has a cylindrical holder 7 integrally cast with the fork lever 3. As shown in FIGS. 1 and 3, this holder 7 has an end wall 7a on the floating lever 4 side, and a pin hole 8 is formed in this end wall 7a to pass through it. This pin hole 8 is formed to have a smaller diameter than the inner diameter of the holder 7, so that one end portion 9a of the pin 9 inserted into the holder 7 so as to be able to move forward and backward can move in and out of the holder 7 through this pin hole 8. It is set as. A torque adjustment screw 10 made of, for example, soft iron is screwed into the opening 7b of the holder 7, facing the other end 9b of the pin 9.
By tightening or loosening the pin 9, the contact load of the torque spring 11, which is a compression spring interposed between the pin 9 and the torque adjustment screw 10, can be adjusted. This torque spring 11 is a compression coil spring made of ordinary spring steel.

What is important is that a ball 23 made of steel, for example, is inserted between the torque spring 11 and the torque adjustment screw 10, and the sphere 23 is held by the torque adjustment screw 10 so as to be rotatable on the axis of the torque adjustment screw 10. A partially spherical recess 24 is formed.
This recessed portion 24 is formed in a shape that makes surface contact with the spherical body 23 on its entire surface.

Torque spring device 6 configured in this way
As shown in Fig. 3, the contact load is as follows: the torque spring device 6 is pressed against the pedestal 25 via the floating lever 4, the holder 7 is once brought into close contact with the floating lever 4, and then the holder 7 is pressed by 1/100 mm. The pressing force when the floating lever 4 is released from the floating lever 4 is measured as the contact load using the push-pull scale 26. Incidentally, the distance between the floating lever 4 and the holder 7 is precisely measured using a dial gauge 27 or the like. Further, in order to protect the torque adjustment screw 10 from the load applied via the push-pull scale 26, the torque adjustment screw 10 is covered with a cap 28 when measuring a close load, and the load is applied from the outside. By adjusting the contact load thus measured to a predetermined value by tightening or loosening the torque adjusting screw 10, variations in governor operation can be corrected.

By interposing the sphere 23 between the torque spring 11 and the torque adjustment screw 10 as described above, when adjusting the tightening or loosening of the torque adjustment screw 10, the sphere 23 can slip between the torque adjustment screw 10 and the sphere 23. can be caused. Due to this slippage, the rotation of the end of the torque spring 11 with respect to the torque adjustment screw 10 is eliminated, and when the torque adjustment screw 10 is tightened or loosened, the torque spring 11
becomes untwisted. As a result, there is no risk of problems such as the torque spring 11 being untwisted due to vibrations during operation and changing the contact load, and there is also no risk of variation in the contact load due to such changes in the contact load. It disappears.
Further, since the end of the torque spring 11 is held on the axis of the torque adjustment screw 10 via the sphere 23, the torque spring 11 is held stably within the holder 7, and the torque spring 11 is held securely. There is no risk that the end of the holder 7 will get caught on the inner circumferential surface of the holder 7, and there is no risk that such a catch will come loose during operation and the adhesion load will change. Therefore, the tightness load can be easily and accurately adjusted by tightening or loosening the torque adjustment screw 10, and the reliability of the governor can be improved. Furthermore, in this embodiment, since the sphere 23 is made of steel having a hardness that is intermediate between the spring steel that makes up the torque spring 11 and the soft iron that makes up the torque adjustment screw 10, it does not absorb the impact force acting from the torque spring 11. The resulting deformation of the end face of the torque adjustment screw 10 can be reduced, and a decrease in the contact load of the torque spring 11 due to such deformation can be prevented for a long period of time, making it possible to further improve the reliability of the governor. .

<Effects of the invention> As described above, in the engine governor torque spring device according to the present invention, a sphere is inserted between the torque spring and the torque adjustment screw, and the sphere is attached to the torque adjustment screw so that the axis of the torque adjustment screw is aligned. The simple structure of forming a recessed part on the top to hold it rotatably makes it easy to reduce the contact load of the torque spring.
And it can be adjusted accurately. Moreover, since there is no possibility that the adjusted contact load of the torque spring will change due to vibrations during subsequent engine operation, etc., accurate and highly reliable adjustment with little variation can be performed.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional plan view of one embodiment of the present invention;
The figure is a side view of a governor equipped with a torque spring device according to an embodiment of the present invention, and FIG.
FIG. 4 is a cross-sectional plan view of a conventional torque spring device. 3... Fork lever, 4... Floating lever, 6... Torque spring device, 7... Holder, 7a... End wall of holder 7, 7b... Opening of holder 7, 8... Pin hole, 9 ...Pin, 9a...
...One end of pin 9, 9b...Other end of pin 9, 10
... Torque adjustment screw, 11 ... Torque spring, 23 ... Sphere, 24 ... Recess.

Claims (1)

[Claims for Utility Model Registration] A pin hole 8 having a smaller diameter than the inner diameter of the holder 7 is passed through the end wall 7a of the cylindrical holder 7, and the pin 9 can be moved forward and backward into the holder 7. One end 9a is inserted through the pin hole 8 so as to move outward from the holder 7, and the torque adjustment screw 10 is screwed into the opening 7b of the holder 7, facing the other end 9b of the pin 9. Arrived,
In the engine governor torque spring device 6 in which a torque spring 11 made of a compression spring is interposed between the pin 9 and the torque adjustment screw 10, there is a sphere 23 that receives the torque spring 11 between the torque adjustment screw 10 and the torque spring 11.
A torque spring device for an engine governor, characterized in that a recess 24 is formed in the torque adjustment screw 10 to hold the sphere 23 rotatably on the axis of the torque adjustment screw 10.