KR0142157B1 - Traveling shift operation structure of farm working car - Google Patents

Abstract

The present invention uses a hydrostatic stepless speed change device (15) having a shift control shaft (15a) acting on a return force to a neutral position by using a shift control tool (10) connected to the shift control shaft (15a). A shift operation mechanism for operating.

A shift operation position holding means 18 is provided for maintaining the shift operation tool 10 at an arbitrary shift operation position, and the shift operation position holding means 18 holds the shift operation tool 10. It has an electromagnetic coil 25 which can be selectively switched between a state and an inactive state of opening the shift control device 10.

Pressure sensing sensors SW1 and SW2 for detecting whether the shift operation tool 10 is in a shift operation state and whether the shift operation tool 10 is stopped at a predetermined shift position are shifted by the shift operation tool 10. When the state is detected, the relay 21 cuts off the electricity supply to the electromagnetic coil.

Description

Shifting mechanism for hydrostatic stepless transmission

The present invention provides a shift control mechanism for manipulating a hydrostatic transmission having a shift control shaft acting on a return force to a neutral position by using a shift control tool connected to the shift control shaft. It is about. Such a shift operation mechanism is particularly suitable for a work vehicle such as a tractor or combine.

(Conventional technology)

Conventionally, as disclosed in Japanese Unexamined Patent Publication No. Hei 4-175562, as a shift operation position holding means, a friction multi-plate retaining mechanism for a shift operation tool is provided at a swing shaft center position of a shift operation tool of a hydrostatic stepless speed transmission apparatus. . Here, the friction plate 10 is arrange | positioned so that the swinging bracket 5 connected to the operation lever 3 may be interposed, and the plate spring 11 presses this friction plate. Due to this fact, the rocking bracket 5, that is, the operating lever 3, is freely restricted. That is, the friction plate 10 and the receiving spring 11 function as the shift lever operating position holding means.

In such a configuration, it is possible to reliably maintain the shift operation position of the shift lever by the frictional force by this holding means, but even when the shift operation tool is operated to a new shift operation position, the friction force is applied, and the operation of the shift operation tool is very heavy. do. This is because the return force to the neutral position of the hydrostatic CVT increases as the position of the shift lever moves away from the neutral position, but the friction force of the position holding means must be at least greater than this maximum return force. That is, even if the shift lever is in any position, a force that exceeds the friction holding force of the position holding means set to a value exceeding the maximum return force described above is required to move the shift lever. This fact has hindered the light touch of the shift lever.

(Summary of invention)

An object of the present invention is to improve the shift operation mechanism for the hydrostatic stepless speed changer as described above, to reduce the operating force during shift operation and to perform a light shift operation and to reliably maintain the position at the shift operation position. In providing a mechanism that can.

The object is that, according to the present invention, a shift operation position holding means provided for maintaining the shift operation tool at an arbitrary shift operation position and an inoperative state for holding the shift operation tool and opening the shift operation tool. It is selectively switchable between, and is solved by providing switching means for switching said shift operation position holding means to at least an inactive state.

In the operating state of the shift control position holding means, the shift control tool is pressed on the support plate and maintained at an arbitrary shift control position. In the inactive state of the shift control position holding means, the pressure acting on the shift control tool is released and the shift control position is maintained. Switching means are provided for switching the means into an inactive state.

According to the above constitution, the holding force applied to the shift operation tool in order to maintain the shift control tool at the set shift operation position can be freely cut when the shift control tool is moved again, if necessary. For this reason, the operation of the shift operation tool becomes light. When the shift operation position holding means is actuated, the shift operation tool can be reliably held by the strong holding force.

In the preferred embodiment of the present invention, if the switching means of the shift operation position holding means is provided in the grip portion of the shift operation tool, the operator can also perform the switching operation on the shift operation position holding means by the hand handling the shift operation tool. The operability is improved more.

As another embodiment, detection means for detecting whether the shift operation tool is in a shift operation state or the shift operation tool in a steady state at a predetermined shift position is provided, and the detection means detects the shift operation state of the shift operation tool. A shift operating mechanism is also proposed, wherein the shifting means is configured to shift the shift operating position holding means into an inactive state.

That is, when the shift operation tool is operated, the detection means detects the shift operation state of the shift operation tool, and the switching means switches the shift operation position holding means to the inactive state based on the detection result. As a result, the holding force of the shift operation position holding means does not act on the shift operation tool. In such an embodiment, when the shift operation mechanism is moved, the holding force of the shift operation position holding means is automatically removed by the action of the detection means, so that the shift operation of the shift operation mechanism is further improved.

In addition, when the shift operation mechanism according to the present invention is interrogated in a work vehicle such as a tractor or combine, the shift operation mechanism is adapted so that the shift means switches the shift operation position maintaining means to an inactive state when the brake of the vehicle is operated. Can be configured. In such a configuration, when the detection means detects the brake operation state of the brake device while the shift operation tool is held at an arbitrary shift operation position, the switching means switches the shift operation position holding means to the inactive state. In this case, since the shift control mechanism is not subjected to the holding force of the shift control position holding means, the shift control tool returns to the neutral position by the return force to the neutral of the hydrostatic stepless transmission. In order to prevent the engine power from being transmitted to the wheels when the brake is operated, it is necessary to return the hydrostatic stepless transmission to the neutral state. This is simplified since the switching means for releasing the holding force of the means is used.

Other features and advantages of the shift control mechanism according to the present invention will become apparent from the description of the embodiments using the drawings below.

(Example)

(First embodiment)

4 shows the structure in the transmission case 2 of the traveling system of the combine, which is one of the working vehicles, and the power from the engine 3 is transferred to the hydrostatic stepless speed change device 15 through the electric belt 4. It is passed to the input pulley (5). The hydrostatic continuously variable transmission is basically a hydraulic pump rotating by engine power, a hydraulic motor driven by pressure oil discharged by the hydraulic pump, and an inclined plate angle of the hydraulic pump to change the rotational speed or rotation direction of the hydraulic pump. It is composed of a shift operation shaft 15a for changing the pressure.

In this embodiment, one power from the output shaft of the hydraulic motor, that is, from the output shaft 1 of the hydrostatic stepless speed changer 15 is transmitted to a harvesting section (not shown). The other power from the output shaft 1 is transmitted to the two-speed sub transmission 6 and is transmitted to the traveling device 8 as a linear driving force through the first clutch 7 in this sub transmission 6. In addition, the power transmitted from the sub transmission 6 to the second clutch 9 is transmitted to the traveling device 8 as a sharp turning and complete turning force.

Here, the rapid turning means turning the vehicle body rapidly by reversing the rotation directions of the right traveling device and the left traveling device, and the complete turning means that the rotating directions of the right traveling device and the traveling device on the left are the same, and the rotation speed The difference is to turn the car body.

The speed change control mechanism for the hydrostatic stepless speed change device 15 is configured to be artificially shifted at any speed in any direction forward and backward by the speed change control device 10. That is, as shown in FIG. 2, the cantilever-shaped support shaft 14 is pulled out from the support frame 23 constituting the machine body, and at the same time, the second operation portion 13 on the cross-sectional channel with respect to the support shaft 14 is provided. ) Is fitted with a loose fit, and the plate-shaped first operation part 12 connected to the arm 11 which forms an operation lever having a grip part on the upper part of the groove of the second operation part 13 is rotatable. Is supported. The shift operation tool 10 is comprised in the 1st, 2nd operation part 12 and 13. The disc spring 24 is attached to the front end side of the second operation part 13 to apply friction holding force to the second operation part 13.

Since the frictional holding force by this disc spring 24 is set very small, it becomes inadequate enough for the shift position holding of the shift operation tool 10, and simply the operation tool of the shift operation tool is given to the operation tool. It is only. In order to realize the purpose of maintaining the shift position of the shift operation tool 10, an electronic shift operation position holding means 18 is provided between the second operation portion 13 and the support frame 23. The shift operation position holding means 18 has an electromagnetic coil 25, and is configured to electronically press the second manipulating portion 13 to the support frame 23 to fix the shift position of the shift operation tool 10. have. The first operating unit 12 and the second operating unit 13 are linked to each other via a connecting pin 19 so as to be interlocked with each other. Therefore, when the shift operation tool 10 is operated in either of the forward and backward directions from the neutral position, the second operation part 13 is interlocked so that the shift operation is performed at an arbitrary position and at the same time the action of the electronic shift operation position holding means 18. The position is maintained even when the hand is released from the shift operation tool 10 at an arbitrary operation position. The shift operation position holding means 18 releases the holding force by a later structure.

In the operating state of the shift operation position holding means 18, the shift operation tool 10 is pressed against the support plates 23 and 17 to be held at the arbitrary shift operation position so that the shift operation position maintaining means 18 In the non-operational state, the pressurization acting on the shift operation tool 10 is released and a switching means 100 capable of converting the shift operation position holding means 18 into the inactive state is provided.

That is, as shown in FIG. 1 and FIG. 2, the connecting pin 19 is integrally fixed to the second operating part 13 in parallel with the support shaft 14, and at the same time, the pin 19 1 Insert the insertion hole 22 formed in the operation unit 12 with a slight gap, and place the pressure sensing switches SW1 and SW2 that are in contact with the connecting pin 19 around the insertion hole 22. Attach to position.

Next, a release structure for the holding state of the electronic shift operation position holding means 18 will be described. By supplying electricity to the electromagnetic coil 25 constituting the electronic shift operation position holding means 18, the second operating portion 13 is pulled to the support frame 23 to hold the rotation of the second operating portion 13 fixed and at the same time. By interrupting the electric supply to the coil 25, the shift operation tool 10 is substantially freed, and the rotation operation of the shift operation tool 10 is made light.

As shown in FIG. 3, the normally closed relay 21 is provided in the electric supply circuit 26 to the coil 25 so as to control the energization state to the coil 25. As shown in FIG. Such a relay 21 is referred to as switching means 100 for shifting the shift operation position holding means 18 into a holding state and a releasing state, that is, an acting state and an inactive state. Accordingly, when the connecting pin 19 comes into contact with the pressure sensing switches SW1 and SW2 so that the pressure sensing switch detects the movement of the shift control mechanism, the relay 21 opens (is blocked) and supplies electricity to the coil 25. Is blocked, and the shift operation position holding means 18 is switched to the inactive state.

In the case where the hydrostatic stepless speed change apparatus 15 is operated by the above configuration, first, the connecting pin 19 contacts the switches SW1 and SW2 so that the supply of electricity to the coil 25 is performed by the relay 21. Blocked, the shift operation position holding means 18 is in an inoperative state, and the shift operation tool 10 can be moved with light force.

30 in FIG. 1 and FIG. 2 is a check pin which checks the shift operation to a reverse state, and stops the movement of the shift control tool 10 by making the check pin 30 abut on the edge part of the guide guide 31. FIG. The check pin 30 is connected to a handle operating tool 32 attached to the grip portion 34 to release the state and to allow the shifting operation to the reverse state.

Next, a configuration for releasing the holding force of the shift operation position holding means 18 in conjunction with the operation of the brake device with respect to the traveling device 8 will be described. As shown in FIG. 3 and FIG. 4, the brake device 29 is attached to one end of the first clutch shaft in the transmission case 2, and the stepped state of the brake operating tool 27 with respect to the brake device 29 is set. The brake sensor 28 is provided in parallel with the pressure detecting switches SW1 and SW2, and the brake sensor 28 detects the brake operation state. Even in this case, the shift operation position holding means 18 is switched to the inactive state by the relay 21. When the shift operation position holding means 18 is switched to the inactive state, and the electromagnetic coil 25 does not function, the holding force for holding the second operation portion 13 by the electromagnetic coil 25 at that position is lost. As a result, the shift operation shaft 15a returns to the neutral position by the neutral return force of the hydrostatic stepless speed change apparatus 15, and the shift operation tool 10 also returns to the neutral position.

(Second embodiment)

In the second embodiment as in the first embodiment, as shown in Figs. 5 and 6, the second operation part 13 in which the shift operation tool 10 is formed by connecting the plate-shaped part to the cylindrical base end, The two operation part 13 is comprised by the plate-shaped 1st operation part 12 rotatably supported by the base end part.

In this second embodiment, the base end portion of the second operating portion 13 is installed around the axial axis as the rotational material, and the support shaft 14 supporting them can be driven by the electric motor 16 with the reduction mechanism. It consists. An electronic shift operation position holding means is fitted between the fixed support plate 17 and the base end of the second operation unit 13 while being fitted by fitting the fixed support plate 17 to the tip of the support shaft 14. 18), the ring-shaped member 13A of the second operating portion 13 is pressed against the fixed support plate 17 by an electromagnetic force to hold the shift operation position. The first operating unit 12 and the second operating unit 13 are linked to each other via a connecting pin 19 so as to be interlocked. Therefore, when the shift operation tool 10 is operated in either of the forward and backward directions from the neutral position, the shift operation position holding means 18 does not act as the electromagnetic force as described above, and the holding force is released to release the first operation portion 12. Accordingly, the second operation unit 13 is interlocked and shifted to an arbitrary position. If the hand is released from the shift operation tool 10 at any operation position and the shift operation tool 10 is stopped, the electromagnetic force of the shift operation position holding means 18 acts, and the shift operation tool 10 is held. The structure of the shift operation position holding means 18 or the switching means 100 is the same as that of the first embodiment.

In this embodiment, the shift control section 10 is provided with an automatic steering control means for automatically operating the electric motor 16 based on the work situation regardless of the shift position of the shift control section 10. That is, the electric motor 16 is controlled to be driven by a control device 20 having a microcomputer, and the engine 3 is provided with a rotation detection sensor S1 for detecting the rotation speed thereof, and a transmission case. (4) is provided with a vehicle speed detection sensor (S2) for detecting the vehicle speed on the basis of the output rotation speed of the built-in sub-shift device (6), the output of each detection sensor (S1, S2) control device 20 Is given to. Since the engine 3 is set to a fully accelerated state during operation, the control unit 20 determines that the engine load is greater than or equal to the preset value when the engine speed becomes less than or equal to the preset value, and automatically decelerates it to a preset vehicle speed. This is to drive control the motor 16. When the electric motor 16 is driven, the first operation part 12 and the second operation part 13 are integrally moved by the shift operation position holding means 18, so that the pressure sensing switch ( Since the SW1 and SW2 are not operated, the shift operation position holding means 18 is in a state in which the operation state is maintained during the operation.

(Third embodiment)

The third embodiment shown in FIG. 7 and FIG. 8 detects whether the shift operation tool 10 is in the shift operation state or the shift operation tool 10 is in the stop state at a predetermined shift position in the first embodiment. It is substantially the same as the detection means SW1 and SW2 to be omitted. The control of the electromagnetic coil 25 is performed by the operation position 50 provided in the grip part 34 of the shift operation tool 10.

This operation switch 50 is connected to the relay 21a provided in the electric supply circuit to the electromagnetic coil 25, and it can control ON / OFF this relay 21a. Moreover, in this embodiment, the plate-shaped 1st operation part 12 connected with the arm 11 is rotatably supported by the support shaft 14 directly.

(Other variations)

a) The shift operation position holding means 18 may be configured so as to be switched between a holding state and a release state by using a clickable engagement and detachment.

b) As a sensor for detecting that the operation of the shift operation tool 10 has been performed, it is provided in the grip part 34 to detect a state in which the grip part 34 is held, and the first operation part 12 causes operation distortion. Sensors installed in other parts, such as capturing a state, may be sufficient, and may not necessarily be pressure sensors. Such a thing is called a detection means collectively.

In addition, although a code | symbol is written in a claim claim for convenient contrast with drawing, by this writing, this invention is not limited to the structure of an accompanying drawing.

1 is a front view showing a shift operation tool according to the first embodiment, (a) is a view showing a state in which the shift operation tool is operated to the reverse position, (b) a shift operation tool is operated to the reverse position,

2 is a partially cutaway side view showing a shift control mechanism according to FIG. 1;

3 is an electric circuit diagram for controlling an electromagnetic coil,

4 is a configuration diagram showing a traveling motorometer,

5 is a front view showing a shift control tool according to the second embodiment, (a) is a view showing a state in which the shift control tool is operated to the reverse position, (b) a shift control tool is operated to the reverse position,

6 is a partially cutaway side view of the shift control tool according to FIG. 5;

7 is a front view showing a speed change control tool according to the third embodiment,

8 is a partially cutaway side view of the shift control tool according to FIG. 7;

* Description of the symbols for the main parts of the drawings *

1: Output shaft 2: Transmission case

3: engine 4: electric belt

5: input pulley 6: sub transmission

7,9: first and second clutch 10: shift operation tool

11: cancer 12,13: first and second control unit

17: fixed support plate 18: shift operation position holding means

19: connecting pin 23: support frame

30: check pin 34: grip

100 (50): switching means (switches)

Claims (7)

Shifting for operating the hydrostatic stepless speed changer 15 having the shifting operation shaft 15a acting on the return force to the neutral position by using the shifting operation tool 10 connected to the shifting operation shaft 15a. As the operating mechanism, In the shift operation position holding means 18 for maintaining the shift operation tool 10 at an arbitrary shift operation position, The shift operation position holding means 18 is selectively switchable between an operating state in which the shift operating tool 10 holds the shift operating tool 10 and a non-operating state in which the shift operating tool 10 is opened; In the operating state of the shift operation position holding means 18, the shift operation tool 10 is pressed against the support plates 23 and 17 to be maintained at the arbitrary shift operation position. In the non-operational state of the shift operation position holding means 18, the pressure acting on the shift operation tool 10 is released, and furthermore, And a switching means (100) capable of switching the shift operation position holding means (18) to an inactive state. 2. The shift operating mechanism according to claim 1, wherein the switching means (100) is a relay (21, 21a) for controlling the supply of electricity to the shift operation position maintaining means (18). . 3. The transmission operation position holding means (18) according to claim 1 or 2, wherein the shift operation position holding means (18) is constituted by an electromagnetic coil (25), and the switching means (100) controls the supply of electricity to the electromagnetic coil (25). A shift control mechanism for a hydrostatic stepless speed change device, characterized in that for shifting the shift operation position holding means (18) at least in an inactive state. The method of claim 1, wherein the detection means (SW1, SW2) for detecting the operation of the shift operation tool 10 is provided, the switching means 100 is based on the detection result of the detection means (SW1, SW2) A shift control mechanism for a hydrostatic stepless speed change device, characterized in that for shifting the shift operation position holding means (18) to the inactive state. 5. The shift control mechanism according to claim 4, wherein said detection means is a pressure reducing switch (SW1, SW2) for detecting an operation of said shift operation tool (10). 5. The shift operating mechanism according to claim 4, wherein said shift operating mechanism is mounted on a vehicle, and said switching means (100) acts on said shift operating position maintaining means (18) when the brake operating tool (27) of said vehicle is operated. A shifting control mechanism for a hydrostatic stepless speed changer, characterized by switching to a state. The shift control mechanism according to claim 1, characterized in that the switching means (100) comprises an operation switch (50) provided on the grip portion (34) of the shift operation tool (10). .