JPS6122019Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is for use in driving a work vehicle, in which a shift lever that can freely swing in a cross direction is configured to be selectively interlocked with a plurality of forward shift shifters and reverse shift shifters. It relates to a speed change operation structure.

This type of work vehicle is required to start from the lowest speed, and if the vehicle is constructed with only two shifters, one for forward and one for reverse, it is difficult to As shown in Publication No. 54-73621, it is possible to intuitively recognize which shifter the gear lever has selected by simply biasing the gear lever toward one of the shifters. However, even when the number of gears increases and the number of forward gear shifters becomes multiple, it is conventionally possible to move the gear lever to the shifter side at one end, as in the example above. Since it was only energized, the lowest speed shifter was located on the energized side and only the lowest speed could be selected, but the high speed shifter and reverse shifter were more important than that. Therefore, it is difficult to select a shifter with a clear distinction between the There was a risk that the vehicle might start moving.

The present invention has a multi-stage driving shift operation structure equipped with a plurality of forward shift shifters and reverse shift shifters. The purpose is to make it possible to start with certainty and to avoid the danger of high-speed start or unexpected reverse by avoiding a mistake in selecting a reverse shifter.

Next, embodiments of the present invention will be described in detail based on the drawings.

A driving front wheel 3 for steering and a driving rear wheel 4, each having a differential device 1, 2, are attached to a vehicle body frame 5,
The engine 6 is located on one side of the front end side of this body frame 5.
A driving unit 7 is mounted on the other side of the engine 6, and the front and rear differentials 1 and 2 are interlocked and connected to the transmission connected to the engine 6 to form a running vehicle body 8.
A transport platform 9 is mounted on the rear of the engine 6 and the driver section 7 to constitute a front wheel steering type four-wheel drive transport work vehicle.

To configure the operation structure of the transmission, as shown in FIGS. 2 and 3, a transmission operation case 11 is attached to a case 10 inside the transmission, and a lid 12 that is detachable from the case 11 is attached to the case 10. A shift lever 13 that can freely swing in a cross direction passing through it in the vertical direction
and a shift rod 14 for reverse operation and third and fourth forward shift rods 15,
and forward first and second shift rods 1
6 are provided so as to be slidable only in the axial direction with their respective shaft ends protruding from the case wall, and shifters 19, 20, 21 are attached to each of them, and the play of these three shifters 19, 20, 21 is An engaging portion b for selectively engaging the engaging piece a at the lower end of the lever 13 is formed on the end side, so that the shift lever 13 can be rotated by swinging in a direction perpendicular to the shift rod axis. and the lowest speed shifter 21 at one end in the swinging direction.
selectively engages the reverse shift shifter 19 on the other end side and the third and fourth shifters 20 in the intermediate portion, and selectively engages the selectively engaged shifters 19, 20,
3 shift rods 14, 15, 16 by 21
By selectively sliding the gear, the transmission connected thereto can be variably operated.

A plurality of shifters 1 are included in the above-mentioned shift operation structure.
A lever biasing mechanism 22 is provided to allow the user to intuitively recognize the shift ranges for the gears 9, 20, and 21. As shown in FIG. 2, this lever biasing mechanism 22 has a hole 23 that passes through the lever axis located at the shifter selection position and whose axis is along the shifter selection swing direction. Hole in case 11,
A cylindrical body 24 in which the hole 23 is threaded on the outside of the case, and the threaded hole has a small diameter portion inside one end in the longitudinal direction and a threaded portion on the inner peripheral surface of the other end.
At the same time as screwing together the Rock Knight 2
5 is attached, and the bottomed cylindrical member 26, which is in constant contact with the lever 13 regardless of shifter operation, is fitted inside the case hole 23, and the inner bottom of the member and the small diameter portion of the cylindrical body 24 are connected to each other. With a first spring 27 interposed therebetween, the shift lever 13
is pressed to a position linked to the lowest speed shifter 21 at the shifter selection position.

Then, the interlocking member 29 provided with the seat 28 at the intermediate portion in the longitudinal direction is fitted into the cylindrical body 24 from the screw hole side, and the screw member 31 provided with the lock nut 30 is screwed into the cylindrical body 24. , this screw member 3
1 and the seat 28, the initial biasing force is changed and set by adjusting the screw member 31.
A spring 32 is interposed between the interlocking member 29 biased by the second spring 32 and the pressing member 26 biased toward the lever by the first spring 27, so that the lever 13 is connected to the lowest speed shifter. 21, forming a gap l in the sliding direction of both members 29 and 26,
Further, the width of this gap 1 is set so that the second spring 32 is not deformed by the pressing action of the shift lever 13 when the shift lever 13 is in a position interlocked with the forward shifters 20 and 21, Then, between the screw member 31 and the interlocking member 29, the lever 13 is switched from the forward operation range to a position interlocked with the reverse shifter 19 against the urging force of the second spring 32 whose urging force is initially set. In addition to forming a gap l ₁ for operation, the gear shift lever 1
A guide plate 33 for 3 is provided.

Although the first and second springs 27 and 32 are provided in series to make the whole structure compact,
Both springs 27 and 32 may be provided separately, or the second spring 32 may be provided in a free state so that the lever 13 comes into contact with the second spring 32 when the lever 13 is interlocked with the reverse shifter 19. Also good.

Further, it is also possible to target a vehicle equipped with three or more forward shifters.

As shown in the above embodiments, the characteristic structure of the shift operation structure for driving a work vehicle according to the present invention is as follows:
In the shift operation structure for traveling of a work vehicle, the structure includes a plurality of forward shift shifters and reverse shift shifters, and a shift lever that can freely swing in a cross direction is configured to be selectively interlocked with each shifter. Each shifter is arranged such that the lowest speed shifter among the plurality of forward shift shifters is disposed at one end and the reverse shift shifter is disposed at the other end in the shifter selection swinging direction of the shift lever. , a lever biasing mechanism is provided for biasing the gear shift lever toward one end where the gear shift lever for the lowest speed is disposed;
The lever biasing mechanism includes a first spring that provides resistance to the selective swing operation of the speed change lever toward the other end side throughout the selection swing range of the speed change lever; The second spring provides resistance only to the operation, and this configuration provides the following effects.

That is, when the shift lever is in the shifter selection position, the shift lever is biased into engagement with the lowest speed shifter, thereby ensuring a low speed start without requiring a judgment to select the low speed shifter. is,
When switching to reverse, the biasing resistance of the first and second springs is applied to the gear shift lever, so you can intuitively know when to switch to the reverse range. Overall, even with a simple modification, low-speed starting is reliable, and it is easy to avoid high-speed starting or unexpected reversing due to incorrect selection of the reverse shifter, and it is easy to operate. Now you can shift gears safely.

[Brief explanation of the drawing]

The drawings show an embodiment of the speed change operation structure for traveling of a working vehicle according to the present invention, FIG. 1 is an overall side view of the work vehicle, FIG. 2 is a sectional view of the speed change operation structure, and FIG. 3 is a plan view of a guide plate. It is a diagram. 13... Gear shift lever, 19... Shifter for reverse gear change, 20, 21... Shifter for forward gear shift, 26
...Lever pressing member, 27...First spring, 29...Interlocking member, 32...Second spring, l...Gap.

Claims (1)

[Scope of utility model registration request] A plurality of forward shift shifters 20 and 21 and a reverse shift shifter 19 are provided, and each shifter 1
9, 20, and 21, each of the shifters 1
9, 20, 21 in the shifter selection swinging direction of the shift lever 13, with the lowest speed one among the plurality of forward shift shifters 20, 21 on one end side, and the reverse shift shifter 19 is disposed on the other end side, and a lever biasing mechanism 22 is provided for biasing the shift lever 13 toward the one end side where the lowest speed shift lever is disposed. , a first spring 27 that provides resistance to the selective swing operation of the speed change lever 13 toward the other end side throughout the selection swing range of the speed change lever 13; and a shifter 1 for switching the speed change lever 13 to reverse.
9. A speed change operation structure for traveling of a work vehicle, characterized in that the second spring 32 provides resistance only to a selection operation of 9.