JPS628186Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a gear shift operation device for a tractor, and when the tractor is equipped with a front loader, blade, or other front-mounted work equipment and frequently changes gears for forward and backward switching, the present invention relates to a gear shift operation device for a tractor. The purpose is to make gear shifting operations effortless, quick and reliable.

When loading a tractor with a front loader, blade, etc., it is necessary to frequently move the tractor back and forth.

For this reason, the gear lever provided on the side of the driver's seat is inserted into an H-shaped guide hole that has a forward height/lower switching guide section and a forward/reverse switching guide section, and is operated along the forward/reverse switching guide section. The forward/reverse switching guide section is located too close to the driver's seat, making it difficult to expect quick operation, and the gear lever is designed to return to a neutral position, which is a communication path for the guide section. Therefore, each time a shift is to be performed, the shift rod must be operated from the connecting path to each guide portion before the actual shift operation is performed, and in this respect as well, the speed of the shift operation is poor.

The present invention was devised in view of the above-mentioned circumstances, and it locates the gear shift rod on the side of the forward/reverse switching guide section where quick switching is required, and makes the position within easy reach from the driver's seat. By locating it far from the target, it is possible to facilitate loading work and speed up gear changes. Therefore, in this invention, the forward height/low switching guide part and the forward/reverse switching guide part are designed as H-shaped guide holes. A gear change guide plate is provided on a fixed side beside the driver's seat, and a gear change lever inserted into the guide hole selectively engages and interlocks a forward height/low speed change interlocking body and a forward/reverse speed change interlocking body, The forward/reverse switching guide part of the guide hole is disposed far from the driver's seat with respect to the forward/lower forward switching guide part, and an elastic body is provided for biasing the speed change lever toward the forward/reverse switching guide part. It is.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 and 2, reference numeral 1 indicates a tractor, and although the front wheels are omitted, the two-axle 4 has rear wheels 2.
It is wheel-shaped. Reference numeral 3 denotes an engine, which is mounted near the front side of the tractor, and is connected to a transmission case 5 via a clutch housing 4 to form a vehicle body 6.

Inside the transmission case 5, there is a traveling system transmission that receives the rotational power of the engine 3 through the engagement and disengagement of a main clutch provided in the clutch housing 4 and rolls the rear wheels 2, and a PTO that drives the PTO shaft 7. It has a built-in system mechanism.

Reference numeral 8 denotes a hydraulic device, which has a pair of left and right lift arms 9 and is placed like a lid on the rear upper surface of the transmission case 5. In this example, a driver's seat 10 is provided above the hydraulic device 8.

On both sides of the driver's seat 10, a pair of left and right fenders 11 are fixed to a rear axle case 12 and erected inside the rear wheel 2, spaced apart in the lateral direction.

A steering wheel device 13 is provided in front of the driver's seat 10, and a main gear shift lever and a PTO are provided on the vehicle body.
A speed change operation device 14 consisting of a speed change lever is provided, and is capable of changing the speed of a main transmission section of a traveling system and a PTO system transmission section, which are respectively built into the transmission case 5.

Reference numeral 15 denotes a speed change operation device according to the present invention, which is provided on the left side of the driver's seat 10 in this example.

Before explaining in detail the embodiment of the speed change operation device 15 according to the present invention, the tractor 1 to which the present invention is applied will be described.
The PTO shaft cover device will be explained with reference to FIGS. 7 and 8.

The outside world protrudes from the rear of the mission case 5.
A so-called saddle-shaped cover 1 is installed on the PTO shaft 7 as a safety device.
6 is provided via a bolt 17. The cover 1
The bolts 6 move so-called due to vibrations during running and work, and abnormal noises are generated due to loosening of the bolts 17 or rattling of the bolts. Therefore, in the illustrated example, an elastic body 19 made of a leaf spring is provided at the center of the back of the cover via a bolt 18, the cover 16 is engaged with a hook 20 on the vehicle body side, and the cover 16 is attached to both side walls of the vehicle body with bolts 17. During installation, the cover 16 is prevented from moving inadvertently by pressing the elastic body 19 against the vehicle body in an elastically compressed state. Therefore, even if the elastic body 19 is a coil spring,
Solid or hollow vibration-proof rubber may be used.

Now, with reference to FIGS. 3 to 5, an embodiment of the speed change operation device 15 according to the present invention will be described in detail while comparing it with the conventional example shown in FIG. 6.

Reference numeral 21 denotes a speed change guide plate, which is fixed to the inside of the vertical surface of the fender 11 via bolts 22 in this embodiment.

Reference numeral 23 indicates a forward/lower forward/lower switching guide; 24 indicates a forward/reverse switching guide; both the guides 23, 24 are provided parallel to each other along the direction of travel of the tractor; An H-shaped guide hole 26 is provided in the speed change guide plate 21 by communicating each neutral portion with a communication path 25. Further, in both guide parts 23 and 24, the forward/reverse switching guide part 24, which has a high frequency of rapid switching, is arranged farther from the driver's seat 10 with respect to the forward height/lower switching guide part 23, on the fender 11 side in this example.

Reference numeral 27 denotes a speed change lever, which is inserted into the H-shaped guide hole 26 and can be operated along both guide portions 23 and 24 and along the communication path 25, and has a grip 2 on its head.
It has 8.

Reference numeral 29 denotes a gear shift rod support, and in this example, a pair of plates 30 and 31 are arranged oppositely and fixed to the outer wall of the hydraulic device 8 via a plurality of bolts 32.
A support shaft 33 is horizontally installed between the plates 30 and 31 via bushing metals 34 and 34, and is rotatable about the shaft.

Reference numeral 35 denotes a forward height/low speed change interlocking body, and numeral 36 represents a forward/reverse speed change interlocking body, which are interlocked and connected via link mechanisms to a forward height/low speed change shifter and a forward/reverse speed change shifter, although not shown.

Reference numeral 37 denotes a cylinder for the forward height/lower linkage body, and 38 denotes a cylinder for the forward/reverse speed change linkage body. Both cylinders 37 and 38 are fitted onto the support shaft 33 between the plates 30 and 31, and are connected to the arms 37A and 37, respectively. 38A, each arm 37
A, 38A are pivotally connected to corresponding interlocking bodies 35, 36 via pins 39, 40.

The former cylinder 37 is fixed on the support shaft 33 via a spring pin or the like, and the latter cylinder 38 is fixed on the support shaft 33.
It is fitted onto the top so that it can rotate freely.

Reference numeral 41 designates a claw lever for advancing and lowering the lever, which is fixed to the outer end of the support shaft 33, extends below the support shaft 33, and has an L-shape having an engaging portion 41A at its extending end.

Reference numeral 42 denotes a forward and backward pawl lever, one end of which is fixed to the cylindrical body 38, extends downward in an L shape, corresponds to the pawl lever 41, and has an engaging portion 42A at its extending end.

In addition, in order to avoid interference with the pawl lever 42, a window hole 43 is formed in the plate 30 over the swinging range of the pawl lever 42.

Reference numeral 44 denotes a speed change lever holder, which is a channel type in this example, and is attached to the support shaft 3 between the pawl lever 41 and the plate 30.
A mantle is fitted on the top of 3 so that it can rotate freely around its axis.
A bifurcated portion 45 connected to the lower end of the speed change rod 27 in the speed change rod holder 44 is located below the support shaft 33 and
It is rotatable via a pin 46 that is perpendicular to
It can be guided along the guide portions 23 and 24 using the support shaft 33 as a fulcrum.

An engaged pin 47 protrudes from the lower end of the gear shift rod bifurcated portion 45, and the engaged pin 47 can be selectively engaged with the engaging portions 41A, 42A of each pawl lever 41, 42. has been done.

Reference numeral 48 denotes an elastic body represented by a coil spring. In this embodiment, the elastic body 48 is interposed between the pawl lever 41 and the gear shift rod bifurcated portion 45 in a resilient manner, going around the support shaft 33.
By making elastic contact with the lower half of 8 below the pin 46 and forming the elastic body abutting portion 49 of the forked portion 45 into a tapered surface, the speed change lever 27 is urged toward the forward/reverse switching guide portion 24. At the same time, the engaged pin 47 is engaged with the engaging portion 42A. Additionally, 50 indicates a thrust collar.

The operation of the embodiment of the present invention constructed as described above will be compared with the conventional example shown in FIG. I will explain.

When carrying out loading work by attaching a front loader (not shown) to the tractor 1, it is necessary to frequently change gears between intermediate forward and low heights and reverse gears. , move the speed change lever 27' to the pin 46' on the driver's seat side (right side in Fig. 6) against the elastic force of the elastic body 48'.
to the fulcrum, engage the pawl lever 42', and move the gear lever 2 along the guide portion 24' with the support shaft 33' as the fulcrum.
By rotating 7', a shifter (not shown) is slid via the interlocking body 36'. According to this conventional example, the speed change lever 27' is moved between the guide portions 24' and 24' by the action of the elastic body 48'.
Since the shift lever 27' is designed to return to the intermediate position of 23', it is necessary to pull in the gear lever 27' each time the gear shift lever 27' is switched forward or backward, and the gear lever 27' must be pulled in toward the driver's seat and rotated back and forth, which is extremely troublesome. It is.

In this regard, in the embodiment of the present invention, the speed change lever 27 is pressed by an elastic body 48 with the pin 46 as a fulcrum.
Since the speed change lever 27 is biased toward the forward/reverse switching guide portion 24 and the engaged pin 47 is engaged with the engaging portion 42A of the pawl lever 42, the speed change rod 27 is pressed during loading work. All you have to do is move it back and forth around the axis of the support shaft 33 along the guide part 24 without having to push or pull it.Moreover, since the guide part 24 is located further away than the driver's seat 10, the operation is easier than in the driver's seat 10. This can be done quickly, and since the gear lever 27 is located at the neutral switching position of the guide section 24, the gear lever 27 is operated around the support shaft 33, and the pawl lever 4
2. A forward/reverse switching shifter (not shown) is operated via the cylindrical body 38 and the interlocking body 36.

In addition, in the embodiment, the biasing elastic body 4 of the speed change lever 27
8, a coil spring wound around the support shaft 33 is pressed against a cam or tapered abutment part 49, but the abutment part 49 is a straight surface, and a guide spring is inserted between the claw lever 41 below the pin 46. A spring may be provided between the supports and the pin 46.
A tension spring may also be provided higher up.

In addition, when performing work other than loading work, such as driving on a general road or plowing work (rotary plowing or plowing), the gear change lever 27 is pulled toward the driver's seat against the elastic body 48, and the engaged pin 47 is engaged with the pawl lever 41. In this state, the gear lever 27 is rotated around the support shaft 33 along the guide portion 23 to swing the interlocking body 35 and slide the gear shifter for switching between heights and lows. There is no problem because the frequency of rapid switching is less than in loading work.

According to the present invention, the forward/reverse switching guide section 24, which is frequently used for rapid switching, is disposed far from the driver's seat 10, and the guide section 24 is provided with an elastic body 48 that biases the gear change lever 27. Therefore, the shifting rod 27 can be reliably positioned by the elastic force of the elastic body 48.
It does not move erroneously even if it receives some vibration, and there is no possibility that it will switch forward or backward due to a malfunction.

Further, since the gear change lever 27 is located in the guide portion 24 that is far from the driver's seat 10, there is an advantage that a quick switching operation can be carried out in a comfortable posture.

[Brief explanation of the drawing]

Fig. 1 is an abbreviated side view of a tractor adopting the present invention, Fig. 2 is a plan view of Fig. 1, Fig. 3 is a rear elevational sectional view of an example of the present invention, Fig. 4 is a plan view of Fig. 3, Fig. 5 is a side sectional view of Fig. 3, Fig. 6 is an elevational sectional view of the conventional example corresponding to Fig. 3, and Fig. 7 is a side sectional view of Fig. 1.
FIG. 8 is an enlarged side sectional view of the PTO shaft cover device, and FIG. 8 is a plan view of FIG. 7. DESCRIPTION OF SYMBOLS 1...Tractor, 10...Driver's seat, 21...Shift guide plate, 23...Forward height/low switching guide part, 24...
...Forward/forward switching guide section, 26...H-shaped guide hole, 27
...speed change lever, 33... support shaft, 35... forward height/low speed change interlocking body, 36... forward/reverse speed change interlocking body, 48...
Elastic body.

Claims (1)

[Scope of utility model registration request] Forward height/low switching guide section 23 and forward/reverse switching guide section 2
4 as an H-shaped guide hole 26
is provided on the fixed side next to the driver's seat 10, and the gear change lever 27 inserted into the guide hole 21 selectively engages and interlocks the forward height/low speed change interlocking body 35 and the forward/reverse speed change interlocking body 36. , an elastic body 48 that disposes the forward/reverse switching guide part 24 of the guide hole 21 at a distance from the driver's seat 10 with respect to the forward/lower switching guide part 23 and biases the speed change lever 27 toward the forward/reverse switching guide part 24;
A tractor speed change operation device characterized by being provided with.