JPH035714Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is based on an operating shaft of a hydraulic transmission that performs continuously variable forward and backward transmission by changing the discharge amount and direction of the pump, and can be held at any operating position via a friction mechanism. This invention relates to a traveling transmission structure in which a transmission lever is linked.

Conventionally, in this type of traveling transmission structure that has been mainly used in combine harvesters and the like, the fixed side member of the friction mechanism has been fixed to the body frame without wobbling.

However, in this case, even if the speed change lever is manually returned to the neutral position to stop the machine from working, the friction mechanism's operating position holding function prevents manual operation from occurring. There is a problem in that it is difficult to position the speed change lever in a completely neutral position, and as a result, it is not possible to ensure a complete stopped state.

In view of the above circumstances, the present invention has an object to provide a mechanism that can reliably solve the problems associated with the conventional structure by simply modifying the friction mechanism.

The characteristic configuration of the traveling transmission structure according to the present invention, which has been made to achieve the above object, is that the fixed side member of the friction mechanism is configured to be freely movable in forward and reverse directions within a certain small range, and the speed change lever is in a position near neutral. At this time, the rotational torque applied to the operating shaft is set to zero or approximately zero depending on the weight balance of the linkage mechanism from the speed change lever to the operating shaft,
The balance correction means is incorporated into the linkage mechanism.

The effects of the present invention having such a characteristic configuration are as follows.

In other words, by utilizing the self-returning force to the neutral position that is basically inherent in the hydraulic transmission due to its continuously variable speed structure, the fixed side member is configured to freely move in the forward and reverse directions. Therefore, it is possible to reliably set and hold the gear shift lever in the neutral position, and at other forward/reverse operation positions, the gear shift lever position and set speed may differ slightly depending on the forward/reverse movement of the fixed side member. Since the above-mentioned free movement is limited to a certain small range, it does not interfere with work traveling.

Moreover, by providing the balance correcting means, the return force, which is not as large as the force on the left, can be effectively applied, and the shift lever can be returned to neutral more reliably.

As described above, focusing on the neutral return force, the fixed side member is intentionally configured to be able to freely move forward and backward within a certain small range, so that it is suitable for any shift operation position of the shift operation lever. Holding accuracy is ensured through a rational configuration that allows for an absolute neutral position that suppresses even the slightest movement of the aircraft at the neutral position, while holding positions that allow some speed fluctuations at other forward/backward positions. We have now been able to provide a traveling transmission structure that allows for easy transmission operations and improved reliability.

Embodiments of the present invention will be described below based on the drawings.

As shown in FIG. 1, a reaping section 4 includes a pulling device 1 for pulling up the planted grain culm, a reaping device 2 for reaping the raised grain culm, a holding and conveying device 3 for transporting the harvested grain culm to the rear, and , a threshing section 7 equipped with an operation control section 5 and a threshing feed chain 6;
A combine harvester is constructed in which a machine body with a rear part thereof is supported by a crawler traveling device 8, and the combine harvester sequentially performs threshing work while reaping a field.

The traveling transmission structure will be described in detail based on FIGS. 2 and 3. A hydraulic continuously variable transmission device 12 transmits power from an engine 11 to a transmission case 10 that supports a drive shaft 9 of a crawler traveling device 8. A gear shift lever 15 has a base end arm 1 which can be held at any operating position via a swinging arm 17 fixedly attached to the operating shaft 13 of the transmission 12 and a friction mechanism 14.
6 are connected to each other by a connecting rod 18 which can be extended and contracted using a turnbuckle system, thereby making it possible to continuously change forward and backward speeds.

As shown in FIG. 3, an axial plunger type hydraulic pump 19 configured to be able to change the discharge amount and discharge direction is connected to the engine 11, and a hydraulic motor 20 is provided on the output side. A charge pump 21 and a charge relief valve 22 are interposed in the hydraulic circuit interposed between the hydraulic pumps 19 and 20, and the operating shaft 13 for changing the angle of the swash plate of the hydraulic pump 19 is rotated by the shift lever 15. By dynamic adjustment, the discharge amount and the discharge direction can be changed. Moreover, the hydraulic pump 19
is its own hydraulic balancing action and friction mechanism 1, which will be described later.
The ability of the fixed side member 23 of No. 4 to freely move in the forward and reverse directions within a certain small range provides a neutral position return force to the shift lever 15, thereby enabling the lever 15 to reliably return to the neutral position.

As shown in FIGS. 3 and 4, a cylindrical boss 25 is penetrated and fixed to the fuselage side frame 24, and a support shaft 27 having a friction plate 26 with a pad 26a integrally fixed to the cylindrical boss 25 is loosely supported, Further, the gear shift lever 15, the friction plate 28 with pad 28a, and the disc spring 29 are disposed on the free end side of the support shaft 27 relative to the friction plate 26.
are sequentially fitted and secured with a nut 30, thereby forming a friction mechanism 14 that can hold the gear shift lever 15 at any operating position, and the support shaft 27.
An engagement groove 27a is provided in the circumferential portion of the cylindrical boss 2.
A pin member 31 that fits into the engagement groove 27a and is movable relative to each other within a certain small range in the circumferential direction is screwed onto the pin member 5.
Therefore, the support shaft 27, that is, the fixed side member 23
is configured to be freely movable in forward and reverse directions within a certain small range.

To configure the gear shift lever 15, an operating member 34 that can move up and down and is biased by an upward spring 33 is housed inside the exterior pipe 32.
A protruding piece 35 that protrudes outward from the pipe 32 extends from the lower end of the pipe 32, and is fitted into a guiding notch 36 that allows the forward and backward rocking movement of the gear shift lever 15 provided on the aircraft frame side. configured to be possible.
Further, a push-in operating tool 37 is provided above the operating member 34, and an arm 38 that can swing up and down is provided between the operating tool 37 and the operating member 34 in a seesaw shape. be, be, be,
By pushing the operating tool 37, the operating member 34 can be pushed against the biasing force of the spring 33. The guiding notch 36 is provided with a stepped portion that can temporarily receive the protruding piece 35 in a state where it slightly enters the reverse position R side at the neutral position N, and the protruding piece 35 is freely movable to the forward position F. However, it is possible to move to the reverse position R by pushing the operating tool 37. Therefore, in the shift operation to the neutral position N, by moving the shift lever 15 to the reverse position R side,
It is possible to eliminate the delay in the support shaft 27 following the shift lever due to the free movement in the forward and reverse directions between the engagement groove 27a and the pin member 31, and to enable a reliable return action to the neutral position N.

The base end arm 16 of the speed change lever 15 is provided with a spring, which is one of the balance correcting means 43 for eliminating the weight imbalance of the linkage mechanism between the speed change lever 15 and the operating shaft 13. , is configured so that the rotational torque applied to the operating shaft 13 due to the weight balance of the linkage mechanism is zero or approximately zero.

FIG. 5 shows another embodiment of the present invention. In this example, a transmission shaft 39 is loosely supported on the cylindrical boss 25 in place of the support shaft 27 without rotation restriction by the pin member 31, and a handling trunk shaft of the threshing section 7 is supported. Torque sensor 40 provided in
The operating force of the speed change operation motor 44, which is automatically operated by the controller 41 based on the workload detection of
The transmission is transmitted to the transmission shaft 39 via the worm gear transmission mechanism 42, and the transmission lever 15 including the friction mechanism 14 is automatically operated, and manual transmission is performed by resisting the frictional force of the friction mechanism 14 as in the previous example. The shift lever 15 is configured to be able to be changed and held at any desired operating position. In this case, due to the backlash of the worm gear transmission mechanism 42, the transmission shaft 39, which is the fixed side member 23 of the friction mechanism 14,
is freely movable in forward and reverse directions within a certain small range, making it possible to return to the neutral position during manual operation as described above.

[Brief explanation of the drawing]

The drawings show an embodiment of the traveling transmission structure according to the present invention, FIG. 1 is a side view of the combine, FIG. 2 is a general rear view, and FIG. 3 is a partially cutaway side view showing the speed change lever and transmission device. FIG. 4 is a sectional view taken along the line -- in FIG. 3, and FIG. 5 is an overall perspective view showing another embodiment. 12...Hydraulic transmission, 13...Operation shaft, 1
4... Friction mechanism, 15... Gear shift lever, 23...
Fixed side member, 43...balance correction means.

Claims (1)

[Scope of utility model registration request] Operation shaft 1 of a hydraulic transmission 12 that performs continuously variable forward/reverse speed by changing the discharge amount and direction of the pump.
3 and a shift lever 15 that can be held at any operating position via a friction mechanism 14 are linked together, and the fixed side member 23 of the friction mechanism 14 can be freely moved in forward and reverse directions within a certain small range. In addition, when the shift lever 15 is in a position near neutral, the shift lever 15 is connected to the operating shaft 13.
A traveling transmission structure in which a balance correcting means 43 is incorporated into the linkage mechanism so that the rotational torque applied to the operating shaft 13 is zero or approximately zero depending on the weight balance of the linkage mechanism during the period of time.