JPS5828251Y2 - Speed change operation device for agricultural tractors, etc. - Google Patents

Description

[Detailed description of the invention] This invention is a gear shift operating device for operating a transmission equipped with multiple gears in agricultural tractors, combine harvesters, riding rice transplanters, etc., more specifically, a gear shift operating lever. The present invention relates to a shift operating device that is provided with an operating shaft that is slidably and rotationally displaced by an operation by a user, and is configured to perform multi-stage gear changes via this operating shaft.

Conventionally, a gear shift operating lever applied to a gear shift operating device that performs multi-speed shifting on an agricultural tractor or the like has been provided by passing through a guide groove of a lever guide plate having a guide groove according to a gear shifting operation pattern such as an H-shape. The gear shifter is operated along the guide groove and selectively brought to each shift action position at each end of the guide groove.

This kind of lever guide plate is used for the gear shift operation mechanism.
・It is placed outside the housing and directly guides the shift operation lever with a large displacement, increasing the overall size of the shift operation device.
Moreover, it often imposes restrictions on the arrangement of other mechanisms.

The purpose of this invention is to construct an extremely compact speed change guide means using the operation shaft in a speed change operation device equipped with an operation shaft as described at the beginning, and to replace the conventional lever guide plate. As an optional feature, it is an object of the present invention to provide a novel speed change operating device for agricultural tractors, etc., which eliminates the above-mentioned problems.

With regard to the illustrated embodiment, the configuration of the speed change operation device for an agricultural tractor or the like according to this invention will be explained first.
A first embodiment shown in FIG. 5 relates to an example in which this invention is implemented as a speed change operating device for operating the speed change device schematically shown in FIG. 1.

As shown in FIG. 2, this transmission is a transmission for rotating a PTO shaft 1 installed at the rear of an agricultural tractor's body at variable speeds. This transmission is arranged between four wheels, which are fixed to the drive shaft 2 and whose diameter increases in this order.
gears 3, 4, 5.6, an idling gear I which is provided with a loose fit on the PTO shaft 1 and is always meshed with the smallest diameter gear 3 on the drive shaft 2, and a spline-fitted gear on the PTO shaft 1. and the axis 1
Three shift gears 8, 9.1 of decreasing diameter in this order are provided so as to be able to freely slide relative to each other but not to rotate relative to each other.
0, of which two shift gears 9, 10 have a common boss part and are integrated into three shift gears 8, 9.
10, and a dog clutch 11 configured by forming one meshing piece 11a on the free rotation gear 7 and the other meshing piece 11b on the first shift gear 8, respectively. ing.

This transmission has a shift gear 8 on the PTO shaft 1,
By selectively displacing 9° 10, the engaging pawl 11a is formed.

11b to engage the dog clutch 11 and connect the free rotating gear 7 to the PTO shaft 1, the gear ratio is 1st gear, and by meshing the shift gear 8 with the gear 4, the gear ratio is 2nd gear. By meshing the shift gear 9 with the gear 5, the gear ratio is 3rd speed, and by meshing the shift gear 10 with the gear 6, the gear ratio is 4th gear.
The TO shafts 1 can be selectively interlocked and connected.

While the transmission is configured as described above, one shift gear 8 and two integral shift gears 9 and 10 in this transmission are selectively slidably displaced on the PTO shaft 1. The speed change operation device for changing the speed of the speed change device is configured as follows.

That is, as shown in FIGS. 2 and 3, the above PTO shaft 1
A fork shaft 12 is provided parallel to and above the fork shaft 12 in a fixed position.
2 includes a shift fork 14 whose lower end fork portion faces into a locking slot 13 formed in the shift gear 8 and engages with the gear 8 in a relatively non-increasable manner; and a engagement formed between the shift gears 9 and 10. The gear 9 faces into the matching groove hole 15 with its lower end fork portion.
Another shift fork 1 that is relatively non-slidably engaged with ゜10
6 and 6 are slidably supported by shifting their positions back and forth.

Similarly to the case, as shown in FIGS. 2 and 3, an operating shaft 17 is supported above and parallel to the fork shaft 12 so as to be slidable and rotatable around the axis.
Two shifters 18 and 19, which are fixed to the operating shaft 17 and have different phases from each other, are provided with their positions shifted back and forth. Of these, the shifter 18 is shifted at a fixed rotational position of the operating shaft 17. The other shifter 19 faces into a retaining groove 14a formed on the upper surface of the fork 14 and engages with the fork 14 in a relatively non-slidable manner. It faces into an engagement slot 16a formed on the upper surface of the fork 16 and engages with the fork 16 in a relatively non-slidable manner.

As described above, by selective rotational displacement of the operating shaft 17, the shifter 18 or 19 on the operating shaft 17 is brought into engagement with the shift fork 14 or 16 as described above. When the operating shaft 17 is slid and displaced in the state that the shift fork 14 or 16 is
As a result, the shift gear 8 or the shift gear 9,10 is slid on the PTO shaft 1, and the operating shaft 17 is selectively slid and rotated. The following operating mechanism is provided for this purpose.

That is, as shown in FIG. 2, the operating shaft 17 extends largely forward, and its front end is located below the front of a passenger seat (not shown) in the illustrated agricultural tractor.
On the front end of the operating shaft 17, as shown in FIGS.
The operating metal fitting 20 forming the a is fitted onto the shaft 17 and the pin 21
are combined and provided.

Similarly, as shown in FIGS. 2 and 4, an operation housing 22 is attached to the upper opening of the fuselage case above the operating hardware 20. A fulcrum shaft 23 is provided so as to be rotatably supported around the end of the axis, and one end of this fulcrum shaft 23 is extended outside the Ujifugu 22, and the fulcrum shaft 23 is connected to the fulcrum shaft 23 at the extended end. The operating lever 24 is provided with a cylindrical portion 24a at the lower end of the lever 24 fitted onto a shaft 33 and fixed to the pin 25, so that the operating lever 24 can be moved along the transverse direction of the machine (direction of arrow A in FIG. 4). When the displacement operation is performed, the fulcrum shaft 23 is slidably displaced, and when the rotation operation is performed in the longitudinal direction of the machine (in the direction of arrow B in FIG. 2), the fulcrum shaft 23 is rotationally displaced around the axis.

Then, the upper end cylinder part 26a is fitted onto the fulcrum shaft 23, and the pin 21'
A fixedly depending shifter 26 is provided, the shifter 26 having a ball portion 26a formed at its lower end facing into the engagement slot 20a in the upper surface of the actuation hardware 20 and engaged with the actuation hardware 20. As a result, due to the rotational displacement of the fulcrum shaft 23, the operating shaft 1 is moved through the shifter 26 and the operating hardware 20.
7 is slid back and forth, and the operating shaft 17 is rotated around the axis via the shifter 26 and the operating hardware 20 due to the sliding movement of the fulcrum shaft 23.

Therefore, first, the operation lever 24 is operated to displace along the direction of the arrow A, and the fulcrum shaft 23 is slidably displaced, thereby obtaining a rotational displacement of the operation shaft 17, and the shifter on the operation shaft 17 is moved. 18 or 19 is engaged with the shift fork 14 or 16, and then the operating lever 24 is rotated in the direction of arrow B to rotationally displace the fulcrum shaft 23, thereby causing the sliding of the operating shaft 17. When the dynamic displacement is obtained, the shift fork 14 or 16 is slid in the same direction,
This allows the necessary gear shifting operations to be performed.

That is, the above-mentioned fulcrum shaft 23 constitutes an operating shaft that is slidably and rotationally displaced by the operation of the operating lever 24, and constitutes an operating shaft through which multi-stage gear changes are performed.

As mentioned above, in particular, the circumferential surface of the fulcrum shaft 23 has a fourth,
Shift guide groove 27 as shown in Fig. 5, that is, operation shaft 17
When the shifters 18, 19 thereon are selectively engaged with the shift forks 14, 16 by rotationally displacing the fulcrum shaft 23, the guide groove portion 27a extends along the axial direction, which is the direction of displacement of the fulcrum shaft 23, and the operating shaft. 17 and selectively slidingly displace the shift fork 14.16 by the shifter 18. A gear shift guide groove 27 is formed which includes guide groove portions 27b and 27b' extending at both ends of the gear shift guide groove 27a. The 28th is coming.

As shown in FIG. 5, the ends of each of the guide groove portions 27b and 27b' having a length shorter than the circumference of the fulcrum shaft 23 are located at the gear shifting operation positions I, II, RI, 1, and 28. The positions are set such that the transmission transmission state at each gear ratio of 1st speed, 2nd speed, 3rd speed, and 4th speed can be obtained by the transmission device in a state facing the respective quantities I, II, III, and IV.

Therefore, when displacing the fulcrum shaft 23 with the operating lever 24, the fulcrum shaft 23 can only be displaced along the shift guide groove 27, restricted by the shift guide groove 27 and the pin 28, and the operation order or operation There is no button that can lead you in the wrong direction.

As shown in FIG. 2, the fork shaft 12 is provided with cutout grooves 29.30 between the neutral position and each shift action position of the shift fork 14.16 thereon. As shown in the figure, each shift fork 14, 16 is provided with a detent means having a ball 33, 34 biased by a spring 3L32 and facing into the notch groove 29, 30.

Next, a second embodiment shown in FIG. 6 will be described. This second embodiment includes a shift gear, etc. (not shown) in a transmission provided directly below the operating lever 24.
Two shift forks 42 and 43 are provided which are slidably supported by two fork shafts 40 and 41, respectively, and which operate and displace shift gears, etc. ing.

A fulcrum shaft 23 similar to that described above is provided, and a shifter pin 44 is fixed to this fulcrum shaft 23 at its upper end and vertically disposed therein.
The shift turbine 44 is moved by the sliding displacement of the fulcrum shaft 23 through the engagement slot 42a at the upper end of the shift forks 42, 43.

43a, and then the shift fork 4 is rotated by the shift turbine 44 which rotates by the rotational displacement of the fulcrum shaft 230.
2.43 is selectively displaced by sliding,
A speed change guide groove 27 similar to that described above is formed on the circumferential surface of the fulcrum shaft 23, and in the case of FIG.
- The ball 45 supported by the housing 22 faces inside the guide groove 27.

It will be understood without further explanation that even in this second embodiment, the speed change operation is regulated by the speed change guide groove 27 and the ball 45, and there is no erroneous operation.

As is clear from the above description, the gear shift operating device for agricultural tractors, etc. of this invention is provided with an operating shaft 23 that can be slid and rotated by operating the gear shift operating lever 24, and a multi-stage shift control device is provided through the operating shaft 23. The speed change operation device is configured to perform a speed change, and includes a guide groove portion 27a that extends along the axial direction of the operation shaft 23 and has a constant length on the circumferential surface of the operation shaft 23, and a guide groove portion 27a of the guide groove portion 27a. A transmission guide groove consisting of a pair of other guide groove portions 27b and 27b' which are connected to each end, extend along the circumferential direction of the operating shaft 23, and have a length shorter than the circumferential length of the operating shaft 23. 2
7, and a pin 28 provided in a fixed position.
Or, with the ball 45 facing inside the speed change guide groove 27,
The guide groove portions 27b at various locations described above constitute the speed change operation guide means.

This configuration is characterized in that the ends of 27b' are set at shift action positions i, n, m, and rv, and has the following advantages.

That is, the speed change operation device of this invention guides the movement of the speed change operation lever 24 by the speed change operation guide means consisting of a combination of the speed change guide groove 27 on the peripheral surface of the operation shaft 23 and the pin 28 or the ball 45 as described above. Since the lever 24 can be operated to each predetermined shift action position by using the lever 24, the lever guide plate conventionally provided outside is not required, and the existing operating shaft 23 and the installation Pin 2! 8 or Ball 4 that requires little space
Since the gear shift operation guide means is configured using 5 and 5, the guide means itself is provided in a compact manner, compared to the conventional gear shift operation which had a shift operation guide means consisting of a lever guide plate. Compared to the operating device, it has a much more compact structure and does not have problems such as restricting the arrangement of other mechanisms.

[Brief explanation of the drawing]

Fig. 1 is a mechanical diagram showing a transmission device operated by a first embodiment of the invention, Fig. 2 is a longitudinal cross-sectional side view of the main part of an agricultural tractor equipped with the first embodiment, and Fig. 3 is a A partially omitted vertical cross-sectional view along the line ■-■ in Figure 2, Figure 4 is I in Figure 2.
FIG. 5 is a longitudinal sectional view taken along the line V-IV, FIG. 5 is a developed view of the main parts, and FIG. 6 is a sectional view showing a second embodiment of this invention. 1...PTO axis, 2...Drive shaft, 3,
4,5゜6...Gear, 7...-Idle gear, 8,9.10...Shift gear, 11...
...Matching clutch, 11at11b...Matching piece, 12...Fork shaft, 14.16...
...Shift fork, 17...Operation axis, 1
8.19...Shifter 20...Operating hardware, 22...Operation...Using, 23...
...Fully shaft, 24...Operation lever, 26...
...Shifter, 27...Shift guide groove, 28
...Pin, 40,41...Fork shaft, 42,43...Shift fork, 44.
...Shifter pin, 46...Ball.

Claims (1)

[Scope of utility model registration request] A shift operating device is provided with an operating shaft 23 that can be slid and rotationally displaced by operating a shift operating lever 24, and is configured to perform multi-stage gear shifting via this operating shaft 23, and the operating shaft 230 has a circumferential surface. A guide groove portion 27a that extends along the axial direction of the operating shaft 23 and has a constant length; and a guide groove portion 27a that extends along the circumferential direction of the operating shaft 23 and that extends from each end of the guide groove portion 27a and that extends along the operating shaft 230. A gear shift guide groove 27 is formed, which is composed of a pair of other guide groove portions 27b and 27b' having a length shorter than that of the station head. facing inside the guide groove 27 and constituting a speed change operation guide means,
The ends of the other guide groove portions 27b and 27b' described above,
A speed change operation device for an agricultural tractor, etc., characterized in that the speed change operation device is set at a speed change operation position.