JPS6329615Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a clutch pedal device for a working vehicle such as an agricultural tractor.

Generally, in this type of work traveling aircraft, when the clutch pedal is depressed in one step, a hydraulic traveling clutch installed separately from the main clutch is disengaged, allowing power to be extracted from the power take-off shaft (PTO shaft) when the aircraft is stopped. There is one in which the main clutch can be disengaged by depressing the clutch pedal further. In some of these types, the travel clutch is constructed with a so-called negative type hydraulic clutch, in which pressurized oil from a hydraulic pump is sent to the clutch side when the clutch pedal is depressed, cutting off power transmission. Conventionally, this was maintained in a loaded state in which pressure oil was sent to the traveling clutch even when the clutch pedal was depressed in two steps. Therefore, even when starting the engine, which requires depressing the clutch pedal to the second depression position before activating the starter, pressure oil is being pumped to the traveling clutch and is under load, so the temperature in winter etc. When the viscosity of the oil is low and the viscosity of the oil is high, the load on the hydraulic system of the travel clutch increases, making it difficult to start the engine smoothly.

The present invention was devised in order to eliminate these drawbacks in view of the above-mentioned actual situation.
The main clutch is disengaged when the clutch pedal is further depressed to the second step, but when the clutch pedal is depressed to the second step, the hydraulic system is automatically stopped by automatically stopping the supply of pressure oil to the travel clutch. The object of the present invention is to provide a clutch pedal device for a work traveling aircraft that can smoothly start the engine in a no-load state even in extremely cold weather. In a working traveling machine configured such that a single step of depression disengages the traveling clutch, and a second further depression disengages the main clutch, the traveling clutch is provided with a hydraulic path communicating with a hydraulic pump. and in the hydraulic path, when the clutch pedal is depressed to the first step, the pressure oil is forced to the traveling clutch to disengage the traveling clutch, and when the clutch pedal is depressed to the second step, the pressure oil is forced to be sent to the traveling clutch. It is characterized in that it is provided with a hydraulic valve that can be switched to disconnect it.

Next, the present invention will be explained in more detail based on the embodiments shown in the drawings. In the drawings, reference numeral 1 denotes the body of an agricultural tractor, and the body 1 includes a main clutch 2 that connects and disconnects power transmission from an engine (not shown), and a drive wheel (rear wheel) 3 with the main clutch 2 in an engaged state. A hydraulic traveling clutch 4 is equipped to interrupt power transmission to and from the vehicle. 5
is a clutch pedal provided at a position that can be depressed from the driver's seat 6, and the boss portion 5a of the clutch pedal 5 is connected to the center case 1a of the fuselage body 1.
It is rotatably supported on a support shaft 1b provided in the.
A plate body 7 is fixed to this boss portion 5a,
A pin shaft 8a provided at the other end of a connecting rod 8 whose one end side is connected to a link 2b protruding from a clutch housing 2a of the main clutch 2 is loosely fitted into a long hole 7a formed in the plate body 7. There is. When the clutch pedal 5 is depressed in one step, which will be described later, the pin shaft 8a only moves the elongated hole 7a from one end to the other without moving the connecting rod 8 at all. Now connect the connecting rod 8 with an arrow
The main clutch 2 is moved in the direction shown in FIG.

On the other hand, a hydraulic valve 10 constituting a hydraulic path communicating the travel clutch 4 with a hydraulic pump 14 via a valve bracket 9 is attached to the step bracket 1c fixed to the center case 1a. A fulcrum shaft 11 whose both ends protrude toward the hydraulic valve 10 side and the clutch pedal 5 side is rotatably supported on the portion. A cam plate 12 is fixed to the end of the fulcrum shaft 11 on the hydraulic valve 10 side, and an operating arm 13 is fixed to the end on the clutch pedal 5 side. In addition, a protruding operating pin 5b is loosely fitted into a cutout groove 13a formed in the operating arm 13 at an appropriate position in the middle of the clutch pedal 5.
When the pedal is depressed, the actuating arm 13 moves to Y along with the cam plate 12.
It is designed to rotate in one direction. The cam plate 12 is formed with a high central cam surface 12a and low cam surfaces 12b and 12c on both sides thereof, and when the clutch pedal 5 is not depressed at all, the spool 10a of the hydraulic valve 10 is As shown in Fig. 2, the hydraulic valve 10 is switched to the OFF side by contacting one of the lower cam surfaces 12b, but the clutch pedal 5 is not pressed to the first step position (position F in Fig. 2).
When the cam plate 12 rotates in conjunction with this, the spool 10a contacts and sinks into the high cam surface 12a as shown in FIG. 5B, thereby switching the hydraulic valve 10 to the ON side. When the clutch pedal 5 is depressed to the second depression position (S position in Fig. 2), the cam plate 12 also rotates further, and the spool 10a moves to the other lower cam surface 12 as shown in Fig. 5C.
The hydraulic valve 10 is configured to be switched to the OFF side upon contact with c. And hydraulic valve 1
0 is switched to the ON side, as shown in FIG. 6, pressure oil from the hydraulic pump 14 is sent to the traveling clutch 4 side to disengage the traveling clutch 4. The switching section in this embodiment is configured.

In addition, in the figure, 15 is a power take-off shaft, 16 is a safety switch that comes into contact with the clutch pedal and turns on when the clutch pedal 5 is depressed to the second step position, so as to operate a starter (not shown). 17
is a hydraulic tank.

In the embodiment of the present invention constructed as described above, in order to extract power from the power take-off shaft 15 while the main body 1 is currently stopped, it is sufficient to depress the clutch pedal 5 to the first depression position F. That is, when the clutch pedal 5 is depressed to the first depression position F, the pin shaft 8a of the connecting rod 8 interlocked with the main clutch 2 side is inserted into the elongated hole 7a of the plate 7 provided in the clutch pedal 5. Since the main clutch 2 is only moved relatively from one end to the other without any movement, the main clutch 2 remains in the engaged state. However, the actuating arm 13 loosely fitted to the actuating pin 5b rotates in the Y direction as the clutch pedal 5 rotates, and therefore the cam plate 12 also rotates in the same Y direction as the actuating arm 13. Therefore, the hydraulic valve 10 is in contact with one low cam surface 12b of the cam plate 12.
The spool 10a, which has been switched to the OFF side, comes into contact with the high cam surface 12a due to the rotation of the cam plate 12. Therefore, the hydraulic valve 10 has been switched to the ON side where pressure oil is sent to the traveling clutch 4 side and the traveling clutch 4 is in a power-off state, and therefore, power is removed from the power take-off shaft 15 in the state where traveling is stopped. It can be taken out.

On the other hand, when the clutch pedal 5 is further depressed to the second step depression position S, the connecting rod 8 moves in the X direction and the main clutch 2 is disengaged. At this time, in this invention, the hydraulic valve 10
will automatically be switched to the OFF side.
That is, the spool 10a is connected to the clutch pedal 5.
In the first step, the high cam surface 12a of the cam plate 12
However, when the clutch pedal 5 is depressed in two steps, the cam plate 12 rotates further in the Y direction, so that the high cam surface 12a contacts the other low cam surface 12b.
2c, the hydraulic valve 10 is automatically switched to the OFF side, and therefore, in this state, no load is applied from the hydraulic system on the traveling clutch 4 side.

In this way, in the present invention, the clutch pedal 5
When the main clutch 2 is depressed in the first step, the traveling clutch 4 is disengaged while the main clutch 2 remains engaged, and when the main clutch 2 is depressed in the second step, the main clutch 2 is disengaged.
When the clutch pedal 5 is depressed to the second step, the clutch pedal 5 is automatically switched to the OFF side by the operation of the switching section described above, and the pressure oil is cut off to the travel clutch 4, and the travel clutch 4 is in the disengaged state. , no load is generated on the hydraulic system. Therefore, when starting the engine, the starter is operated after depressing the clutch pedal 5 to the second depression position and turning on the safety switch 16, but in this case, the hydraulic valve 10 is switched to the OFF side and the hydraulic system is closed. Since there is no load on the engine, the engine can be started smoothly and easily even in extremely cold weather when the oil viscosity is extremely high. Moreover, this one is simply the cam surface 12
It is convenient that the cam plate 12 having the elements a, 12b, and 12c can be constructed with an extremely simple structure in which the clutch pedal 5 is rotated integrally with the cam plate 12.

It goes without saying that the present invention is not limited to the embodiments described above, but the present invention can also be implemented, for example, in the second embodiment shown in FIGS. 7 to 9. . That is, in the second embodiment, one of the links 19 and 20 rotatably supported on the common pivot 18
is interlockingly connected to the boss portion 5a of the clutch pedal 5 via the connecting rod 21, and is also interlockingly connected to the actuating body 23 of the hydraulic valve 10 via the inner wire 22, and further connected to the main body of the fuselage via the first bomber 24. It is held on the 1st side. When the clutch pedal 5 is depressed, the link 19 rotates against the biasing force of the first bomb 24 to pull the inner wire 22 and switch the spool 10a of the hydraulic valve 10 to the ON side. The other link 20 is
Outer wire 2 covering the inner wire 22
One end of the second bullet 2a is fixed, and the second bullet is set so that the initial tension is approximately equal to the biasing force of the first bullet 24 that is extended when the clutch pedal 5 is depressed to the first depression position. It is supported on the fuselage main body 1 side via the fuselage 25. When the clutch pedal 5 is depressed in one step, only one link 19 rotates to open the hydraulic valve 10 as described above.
When the clutch pedal 5 is switched to the ON side, and the clutch pedal 5 is further depressed, the other link 20 rotates together with one link 19 against the second bullet 25 due to the pushing force of the outer wire 22a. Therefore, the operator can sense the weak depression resistance caused by the first bullet 24 when the traveling clutch 4 is depressed in one step, and
In the second stage of depression in which the main clutch 2 is disengaged, strong depression resistance from both the first and second bullets 24 and 25 can be sensed to prevent any mistakes in depression. In the second embodiment, the other link 20
The support body 27 and the hydraulic valve 10 are rotatably provided in the
A connecting wire 26 is connected between the spool 10b and the other spool 10b.
has been erected. When the clutch pedal 5 is depressed in one step, the link 20 does not rotate at all, so the connecting wire 26 is not pulled.
As described above, the hydraulic valve 10 is set to the ON side by switching one spool 10a, but when the clutch pedal 5 is further depressed, the connecting wire 26 is pulled this time, switching the other spool 10b to the OFF side. The pressure oil is cut off from being fed to the travel clutch 4. Therefore, even in the case of the second embodiment, there is no load from the hydraulic system when the main clutch 2 is disengaged, so that the engine can be started smoothly and easily. As described above, the second embodiment is effective when the hydraulic valve is far away from the clutch pedal 5, but even in this case, the spool 10
It is also possible to construct the actuating body for actuating a by a cam plate as in the first embodiment.

In summary, the present invention provides a working traveling machine configured such that the traveling clutch is disengaged when the clutch pedal is depressed one step, and the main clutch is disengaged when the clutch pedal is further depressed two steps.
The traveling clutch is provided with a hydraulic path communicating with a hydraulic pump, and in the hydraulic path, when the first step of the clutch pedal is depressed, pressure oil is sent to the traveling clutch to disengage the traveling clutch, and the second step of the clutch pedal is depressed. Since there is a hydraulic valve that switches to cut off the pressurized oil supply to the travel clutch when the clutch pedal is depressed, the travel clutch is disengaged when the clutch pedal is depressed in one step, but the clutch pedal is pressed down two steps further. When the clutch is depressed to the depressed position, the pressure oil supply to the traveling clutch is automatically stopped, and as a result, in this state, no load is applied from the hydraulic system side of the traveling clutch 4. Therefore, when starting the engine, which requires operating the starter with the clutch pedal in the second depressed position, no load is applied from the hydraulic system, and the viscosity of the oil remains high. The engine can be started smoothly and easily even in extremely cold weather.

[Brief explanation of the drawing]

The drawings show an embodiment of the clutch pedal device for a working traveling body according to the present invention, in which FIG. 1 is an overall side view of the traveling body, FIG. 2 is a side view of the main part, and FIG. 3 is a side view of the main part. A perspective view of the main part, Figure 4 is an enlarged view of the main part,
Figures 5A, B, and C are action explanatory diagrams, Figure 6 is a hydraulic system diagram, Figures 7 to 9 show the second embodiment, Figure 7 is a side view of the main part, and Figure 8 is a diagram showing the hydraulic system. FIG. 9 is a rear view of the main parts, and FIG. 9 is a front view of the main parts of the hydraulic valve. In the figure, 2 is the main clutch, 4 is the travel clutch, 5 is the clutch pedal, 10 is the hydraulic valve, 1
0a is a spool, and 12 is a cam plate.

Claims (1)

[Scope of utility model registration request] In a work traveling machine configured such that the traveling clutch is disengaged when the clutch pedal is depressed in one step, and the main clutch is disengaged when the clutch pedal is further depressed into the second step, the traveling clutch is connected to hydraulic pressure connected to a hydraulic pump. A path is provided, and in the hydraulic path, when the clutch pedal is depressed to the first step, pressure oil is sent to the traveling clutch to disengage the traveling clutch, and when the clutch pedal is depressed to the second step, the pressure oil is supplied to the traveling clutch. A clutch pedal device for a work traveling machine, characterized in that it is provided with a hydraulic valve that switches to cut off pressure feeding.