JPH08104149A - Power taking-out device for working vehicle - Google Patents

Abstract

PURPOSE: To set a mid PTO shaft close to a power transmission case, by installing a hollow cylindrical center pivot part on an axle or a power transmission case, in a swingable manner, supporting a PTO shaft on the other side, inserting a transmission shaft into the inner hole of a center pivot part and interlocking-connecting the transmission shaft with the PTO shaft. CONSTITUTION: An axle case F is constituted so as to be swingable in the lateral direction at the longitudinal axis center of a center pivot part X between a power transmission case K and a bearing device 36, and the rear end of the transmission shaft 20b acts at a center pin shaft. On the axle case body Fa and a cover body Fb, the first PTO shaft 21 is horizontally laid, and the shaft end is projected rearward, and a space G is formed therebetween, and at the part of the transmission shaft 20b which crosses inside, a fixed gear 59 is installed, and meshed with a fixed gear 60 on the first PTO shaft 21, and each revolution of the transmission shafts 20a and 20b is transmitted to the first PTO shaft 21. The first PTO shaft 21 as mid PTO drives a working machine, and the length of the transmission shaft for connection can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power take-out device for driving a work machine in a work vehicle such as a tractor.

[0002]

2. Description of the Related Art Conventionally, there has been known a technique in which a power transmission case suspended from a vehicle body frame is provided in front of an axle case which pivotally supports a pair of steering wheels.
For example, it is like the technique described in Japanese Utility Model Laid-Open No. 58-80318. However, the power transmission case is a dedicated power transmission case for driving a working machine such as a snow remover mounted in front of the vehicle body.

When a work machine is mounted on the lower abdomen of a vehicle body, a technique such as Japanese Utility Model Laid-Open No. 60-134023 is adopted. In this case, in a transmission mission that drives fixed wheels, a mid-PTO shaft is arranged in the abdomen of the mission case so that engine power synchronized with the input rotation of the transmission can be taken out.

[0004]

According to the former prior art, the power transmission case does not interfere with the center pin device for swingably supporting the axle case around the longitudinal axis so as not to interfere with the body frame. There was a problem that the front-rear length of the fuselage became large because it was placed closer to the front of. Further, according to the latter conventional technique, the transmission system of the mid PTO shaft is accommodated in the mission case together with the drive system of the fixed wheels, so that the mission case becomes large-sized and the mid PTO shaft approaches the rear wheel side. In other words, the transmission shaft for connection to the working machine arranged on the lower abdomen of the vehicle body tends to be elongated. The main object of the present invention is to arrange the mid PTO shaft, which has been conventionally arranged in a fixed wheel drive mission case, on the side of the axle case, and to prevent the axle case from swinging in the left-right direction. PTO
It is to be arranged as close as possible to the power transmission case that drives the shaft.

[0005]

The problems to be solved by the present invention are as described above. Next, the means for solving the problems will be described. According to the first aspect of the present invention, a power transmission case having a transmission shaft driven by engine power is hung on the vehicle body frame on one side of the front and rear sides of the axle case that pivotally supports a pair of steering wheels. Alternatively, the power transmission case is provided with a hollow cylindrical center pivot portion X having a front and rear axis, and the axle case and the power transmission case are connected to each other via the center pivot portion X so that the axle case swings around the center pivot portion X. While freely configured,
A first PTO shaft is supported on the other side of the axle case, and a power transmission shaft driven by the engine power is provided in the power transmission case. The power transmission shaft is inserted into the inner hole of the center pivot portion X, and the first PTO shaft is inserted. It was linked to the shaft.

According to a second aspect of the present invention, there is provided a propulsion shaft for driving the steering wheel provided on the axle case, and the first shaft.
The PTO shaft and the PTO shaft are arranged side by side in the vehicle width direction.

According to a third aspect of the present invention, the power transmission case is integrally formed with a hydraulic pressure supply device including a hydraulic pump for driving the hydraulic actuator with the lubricating oil in the case.

According to a fourth aspect of the present invention, the power transmission case is equipped with a second PTO shaft driven by receiving engine power.

[0009]

Next, the operation will be described. According to the first aspect of the present invention, the front and rear sides of the axle case are connected to the power transmission case via the center pivot portion. Therefore, the axle case is referred to as the center pivot portion while the both are arranged as close to each other as possible. Swing left and right around the heart. The first PTO shaft arranged on the axle case side is a mid PT for driving the working machine arranged on the lower abdomen of the vehicle body.
It functions as an O-axis and requires only a short transmission shaft for connection to the work machine. Further, since the transmission shaft of the power transmission case for driving the first PTO shaft is concentrically arranged with respect to the center pivot portion, the transmission shaft does not become an obstacle when the axle case swings.

In the second aspect, since the propulsion shaft and the first PTO shaft are juxtaposed in the width direction of the vehicle body, the PTO shaft projecting to the rear of the axle case swings as the axle case swings, It is possible to drive the steering wheel and the working machine without interfering with each other.

According to a third aspect of the present invention, as the actuator, for example, a power steering cylinder for steering and driving the pair of steering wheels is provided, or the first P
When a hydraulically actuated clutch that enables connection and disconnection of power transmission to the TO shaft is provided, the hydraulic supply device pumps up the lubricating oil in the power transmission case and drives them.

According to the fourth aspect, the second PTO shaft mounted on the power transmission case functions as a front PTO shaft for driving the working machine mounted on the front portion of the vehicle body, and can be used for various work applications. .

[0013]

EXAMPLES Next, examples will be described. FIG. 1 is an overall side view of a tractor equipped with a power extraction device for a work vehicle according to the present invention, and FIG.
3 is a front view of the tractor of FIG. 1, FIG. 4 is a plan view of FIG. 3, FIG. 5 is a side sectional view of a front portion of the engine E, a power transmission case K and an axle case F, and FIG. A-
5 is a sectional view taken along the line BB of FIG. 5, FIG. 8 is a sectional view taken along the line C-C of FIG. 5, and FIG. 9 is a sectional view taken along the line D-D of FIG. FIG. 11 is a side sectional view of a portion of the axle case F and the differential device DF, and FIG. 11 is a top sectional view of a portion of the PTO clutch 15.

Referring to FIG. 1, the overall construction of a tractor equipped with the power take-out device for a work vehicle according to the present invention will be described. The engine E is mounted on the anti-vibration between the left and right body frames 3 and 3,
A damper housing accommodating the damper device 13, an HST case H, and a mission case M are arranged in succession in the rear of the engine E to form a machine body. The damper device 13 is mounted on the crankshaft protruding rearward from the engine E, and the engine power via the damper device 13 is transmitted via the connecting shaft 39 to the hydraulic continuously variable transmission and the transmission case M in the HST case H. Through the gear transmission in
The fixed (rear) wheel 8 is driven by the rear axle protruding from the mission case M.

Further, the rotation that has passed through the hydraulic continuously variable transmission in the HST case H is transmitted to the differential device DF in the axle case F via the front wheel drive connecting shaft 23 so that the steering to the axle case F is possible. The steered (front) wheels 7, 7 that are mounted are driven. Further, a power transmission case K is suspended and supported at a position near the front of the vehicle body frame 3,
At the lower position of the power transmission case K, there is a second protrusion protruding forward.
(Front) PTO shaft 11 is equipped. The axle case F has a first (mid) PTO shaft 2 protruding rearward.
A lawn mowing work machine R equipped with 1 and mounted on the lower abdomen of the vehicle body is driven via a connecting transmission shaft 6.

A steering valve device 1 is arranged above the damper case 9, and a steering handle 5 is arranged above the steering valve device 1. Reference numeral 17 denotes a hydraulic lift device for lifting and lowering a working machine such as a rotary tiller connected to the rear portion of the vehicle body.

In FIG. 2, the entire power transmission system will be described in detail. The charge pump CP and the hydraulic pump P are driven by the input shaft 28 connected to the rear end of the connecting shaft 39. The input shaft 28 penetrating the hydraulic pump P and protruding rearward protrudes inside the transmission case M, and the fixed gear 40 at the rear end of the shaft 28 and the loose fitting gear 41 at the front end of the rear PTO transmission shaft 29 are connected. It is meshed. A rear PTO clutch 18 is arranged in front of the rear PTO speed change shaft 29 so that the loose fitting gear 41 and the rear PTO speed change shaft 29 can be engaged and disengaged.
Gears 47 and 48 are fixedly provided at the rear of the rear PTO transmission shaft 29, and are constantly meshed with loose fitting gears 49 and 50 on the PTO counter shaft 30. Then, the shift shifter 51, which is rotatable relative to the PTO counter shaft 30 and is slidable in the axial direction, is slid forward and backward to be engaged with either of the loose fitting gears 49 and 50.
The high and low second speed can be obtained on the O counter shaft 30.

The fixed gear 52 at the rear end of the PTO counter shaft 30 meshes with the fixed gear 53 on the rear PTO shaft 16 to drive the third (rear) PTO shaft 16. The hydraulic motor Mo is driven by the pressure oil discharged from the hydraulic pump P to form a hydraulic continuously variable transmission. The output shaft 22 of the hydraulic motor Mo is projected in front of and behind the HST case H. A fixed gear 42 at the rear end of the output shaft 22 meshes with a fixed gear 43 in front of the speed change counter shaft 31, and a fixed gear 46 is provided behind the speed change counter shaft 31.
A loose fit gear 44 and a shift gear 45 that is non-rotatable and slidable in the axial direction are provided on the shift shaft 32, and the loose fit gear 44 is always meshed with the fixed gear 43. By engaging the speed change gear 45 with the loosely fitting gear 44 or with the fixed gear 46, two high and low speed speed changes can be obtained on the speed change shaft 32.

The front protruding portion of the output shaft 22 is connected to the rear end of the first propulsion shaft 24 via the front wheel drive connecting shaft 23. A front wheel drive clutch 25 is interposed between the first propulsion shaft 24 and the second propulsion shaft 33. The second propulsion shaft 33
Fixed gear 61 on the shaft and fixed gear 62 on the pinion shaft 34
And are in mesh. The pinion portion at the tip of the pinion shaft 34 meshes with the differential ring gear of the differential device DF. Front axles 12, 12 project from the differential device DF to the left and right.

Next, the power transmission case K and its related portions will be described with reference to FIGS. 2 and 5. That is, the elastic coupling 2 having the driven shaft 19 is connected to the portion of the engine E where the crankshaft projects forward. The power transmission case K includes a case body Ka and a lid body K.
b is joined to each other in the front-rear direction, and as shown in FIG. 8, a protruding portion K extending in the left-right direction is provided in a substantially middle portion of the lid body Kb.
C and Kc are fixed to the left and right vehicle body frames 3 and 3 so as to be suspended. The input shaft 27, the intermediate shaft 35, and the transmission shaft 20 are provided between the case body Ka and the lid Kb.
a, the second PTO shaft 11 is horizontally mounted so that they are parallel to each other. One end of the input shaft 27 projects rearward from the lid body Kb and is connected to the driven shaft 19 via the connecting shaft 26, and the other end is exposed on the front surface of the case body Ka, and the hydraulic pump FP mounted on the front surface. It is connected to the pump shaft of and drives this. A gear 54 is fixed to a portion of the input shaft 27 located inside the power transmission case K, the fixed gear 54 meshes with a gear 55 on the intermediate shaft 35, and the gear 55 is loosely fitted on the transmission shaft 20a. It meshes with the gear 56. A PTO clutch 15 is interposed between the loose fitting gear 56 and the transmission shaft 20a so as to engage and disengage the both. The fixed gear 57 at the front end of the transmission shaft 20a meshes with the fixed gear 58 on the second PTO shaft 11. The shaft end of the second PTO shaft 11 projects forward from the case body Ka and is used to drive a working machine such as a snow blower mounted in front of the vehicle body.

The axle case F arranged at the rear of the power transmission case K is constructed by joining a case body Fa and a lid body Fb to each other in the front and rear, and as shown in FIG. 7, inside the case body Fa. The differential device DF and the axle shaft 12 are housed. And, on the front surface of the case body Fa,
Hollow cylindrical center pivot part X with a longitudinal axis
Are integrally formed. On the other hand, on the rear surface of the lid Kb of the power transmission case K, the center thereof is the transmission shaft 20a.
A circular hole Kd that coincides with the shaft center is provided, the center pivot portion X is fitted into the bearing through a bearing 100, and the transmission shaft 20a extends concentrically therein.
Further, a transmission shaft 20b extending in the front-rear direction coinciding with the front-rear axis of the center pivot portion X is housed and supported in the axle case F, and a front end of the transmission shaft 20b is provided with a joint 101 at the shaft end of the transmission shaft 20a. The rear end projects from the lid Fb rearward. On the other hand, a bearing device 36 is provided horizontally between the left and right frames 3 and 3 behind the axle case F, and the rear end of the transmission shaft 20b is supported by the bearing device 36 so as to be rotatable around its axis. It is supposed to be done.

Therefore, the axle case F has a center pivot portion X between the power transmission case K and the bearing device 36.
Of the front and rear shafts, that is, around the transmission shafts 20a and 20b, is swingable in the left and right directions.
The rear end of b functions as a center pin shaft. The case body Fa and the lid body Fb of the axle case F have the first P
The TO shaft 21 is laid horizontally, and its shaft end is projected rearward. A space G is formed between the case body Fa and the lid Fb, and a fixed gear 59 is provided at a portion of the transmission shaft 20b that traverses the space G, and the fixed gear 59 is the first.
It meshes with the fixed gear 60 on the PTO shaft 21, and the transmission shaft 2
The rotation of 0a and 20b is configured to be transmitted to the first PTO shaft 21. In the present embodiment, the two transmission shafts 20
Although assembling is simplified by connecting a and 20b with the joint 101, it is also possible to configure as one transmission shaft 20.

In the space G formed in the case body Fa and the lid Fb of the axle case F, as shown in FIG. 10, power transmission means for the differential device DF in the case body Fa is further constructed. That is, the hydraulic motor M
A cover 24a bearing-supporting the first propulsion shaft 24 to which speed change power is applied from o is mounted on the rear surface of the lid Fb, and is disengaged from the first propulsion shaft 24 via the front wheel drive clutch 25. The propulsion shaft 33 extends laterally between the case body Fa and the lid Fb so as to be arranged concentrically with the first propulsion shaft 24, and a pinion shaft 34 having a pinion portion that meshes with the differential ring gear of the differential device DF is provided. Second propulsion shaft 3
It is laid across the space between the case body Fa and the lid Fb in parallel with 3. The power transmission means is configured by constantly engaging the fixed gear 62 on the pinion shaft 34 with the fixed gear 61 on the second propulsion shaft 33. Then, as shown in FIG. 7, the first and second propulsion shafts 24 and 33 and the first PTO shaft 21 are laid out so as to be juxtaposed with each other in the vehicle width direction.

3 and 4, the control valve 4 of the PTO clutch 15 is fixedly installed on the upper side of the case body Ka of the power transmission case K as shown in the front view and the plan view of the front part of the tractor. And a hydraulic pump F on the front
A pump case 14 accommodating P is mounted, and on the front surface of the pump case 14, a hydraulic pressure take-out port 63 for using the pressure oil discharged by the hydraulic pump FP as a hydraulic power source of the power steering cylinder 37, and a return oil port. 64 are provided so as to be opened, and each port has a steering valve device 1
Piped to. In the pump case 14 of the hydraulic pump FP, as shown in the hydraulic circuit portion of FIG. 11, a pressure reducing valve type flow dividing valve V1 that divides the oil discharged from the hydraulic pump FP into two directions and the flow dividing valve V1 are operated. A resistance valve V2 for controlling the pressure and a relief valve V3 that regulates the operating pressure of the power steering cylinder are housed to form a hydraulic pressure supply device. Then, the lubricating oil in the power transmission case K pumped up by the hydraulic pump FP is divided by the shunt valve V1, and the pressure oil output from the first shunt port is used to operate the PTO clutch 15 through the control valve 4. The pressure oil output from the second branch port is used to drive the power steering cylinder 37 through the steering valve device 1.

The power steering cylinder 37 is laterally installed inside the vehicle body frame 3 above the axle case F, and as shown in FIG. 4, the cylinder base portion 37a is fixed to the vehicle body frame 3 and the piston rod 37b is attached to the front wheel. It is connected to a knuckle arm 7a provided on one side of 7,7. A pair of front wheels 7, 7 is a power steering cylinder 3
When 7 is expanded and contracted, they are linked to each other so as to steer around a vertical axis that is slightly inclined inward of the vehicle body.

In FIG. 6, the joint surface of the lid Kb of the power transmission case K to the case body Ka is shown, and an oil groove 70 extending in the vertical direction is provided in the joint surface. The lower end of the oil groove 70 is connected to an oil filter 71 which is horizontally mounted on the bottom of the case body Ka, and the upper end of the oil 70 is a hydraulic pump FP which is open at the joint surface of the case body Ka.
Of the suction port 72. Therefore, the power transmission case K also serves as an oil tank for the hydraulic pump FP, and the lubricating oil in the power transmission case K is in the oil groove 70.
The oil filter 71 filters the oil when it is sucked into the hydraulic pump FP via.

The thickness of the case body Ka of the power transmission case K is between the input port of the control valve 4 for connecting and disconnecting the PTO clutch 15 and the first diversion port of the diversion valve V1 of the pump case 14. It is connected by an oil passage (not shown) provided in the wall. Further, as shown in FIG. 11, an oil passage inheritance portion 20c connected to the oil chamber 15a of the PTO clutch 15 is formed at the shaft end of the transmission shaft 20a on the side supported by the case body Ka of the power transmission case K. The control valve 4 for the oil passage inheritance portion 20c.
Is connected to the case body Ka through an oil passage 84 provided in the thick wall of the cover body Kb. A friction pad 80 is arranged at a position on the outer side of the clutch housing 85 of the PTO clutch 15 to configure a follow-around prevention brake. That is, when the PTO clutch 15 is in the engaged state by the control valve 4, the follow-up prevention actuator 81 is driven by the oil pressure introduced into the oil passage 84.
Moves the friction pad 80 in the direction away from the outer periphery of the clutch housing 85 against the biasing force of the spring 82, and P
The TO clutch 15 can be rotated. When the control valve 4 is switched and the PTO clutch 15 is in the disengaged state, the entrainment prevention actuator 81 projects due to the urging force of the braking spring 82, the friction pad 80 is pressed against the clutch housing 85, and the PTO Clutch 15
Prevents the rotation of the car. In the case body Ka of the power transmission case K, a PT is provided at the opening end of the oil passage 84.
Relief valve 8 for regulating the operating pressure of the O-clutch 15
3 are provided. The oil pressure of the oil passage 84 is the relief valve 8
The oil which is adjusted to a constant pressure by 3 and is relieved when the pressure becomes equal to or higher than the specified pressure is supplied as the lubricating oil of the friction plate of the PTO clutch 15 through the oil passage provided in the transmission shaft 20a. .

[0028]

The present invention has the following effects. According to the first aspect of the invention, the front and rear sides of the axle case are connected to the power transmission case via the center pivot portion, so that the axle case and the power transmission case can be arranged as close to each other as possible. Although it is possible, the axle case can swing in the left-right direction about the front-rear axis center of the center pivot portion. Then, the first PTO shaft arranged on the axle case side can act as a mid PTO shaft to drive the work machine arranged on the lower abdomen of the vehicle body and shorten the transmission shaft for connection to the work machine. Further, the transmission shaft for driving the first PTO shaft of the power transmission case is concentrically arranged with respect to the center pivot portion, so that the transmission shaft does not become an obstacle when the axle case swings.

According to the second aspect, the propulsion shaft and
The first PTO shaft is juxtaposed in the width direction of the vehicle body, and the PTO shaft projecting to the rear of the axle case swings together with the axle case and swings to drive the steering wheel and the working machine.
This can be done without interference, and even if the first PTO shaft is arranged on the axle case side, it is possible to avoid lowering the ground clearance of the airframe.

Since the actuator is provided with, for example, a power steering cylinder for steering and driving the pair of steering wheels, or the connection of power transmission to the first PTO shaft is connected / disconnected. In the case of providing a hydraulically actuable clutch that enables the above, since the hydraulic pressure supply device can pump up the lubricating oil in the power transmission case and drive them, it is not necessary to mount a dedicated oil tank on the machine body. The advantage is that the entire body can be made compact. Also, power steering cylinder and PTO
Like a clutch, pressure oil is supplied from a hydraulic pump arranged in front of the engine to a hydraulic actuator arranged in front of the engine E, so that the oil passage can be shortened and pressure loss can be suppressed. It was.

According to the fourth aspect of the invention, the second PTO shaft mounted on the power transmission case functions as a front PTO shaft for driving the working machine mounted on the front part of the vehicle body and supports various work applications. be able to.

[Brief description of drawings]

FIG. 1 is an overall side view of a tractor equipped with a power take-out device for a work vehicle according to the present invention.

FIG. 2 is a development schematic diagram showing an overall power transmission configuration of a work vehicle.

FIG. 3 is a front view of the tractor of FIG.

FIG. 4 is a plan view of FIG.

FIG. 5 is a side sectional view of a front portion of the engine E, a power transmission case K, and an axle case F.

6 is a cross-sectional view taken along the line AA of FIG.

7 is a cross-sectional view taken along the line BB of FIG.

8 is a cross-sectional view taken along the line CC of FIG.

9 is a cross-sectional view taken along the line DD of FIG.

FIG. 10 is a side sectional view of a portion of an axle case F and a differential device DF.

FIG. 11 is a top sectional view of a portion of a PTO clutch 15.

[Explanation of symbols]

 E engine F axle case K power transmission case M transmission case X center pivot part 4 control valve 11 second (front) PTO shaft 15 PTO clutch 20 center pin shaft 21 first (mid) PTO shaft 24 propulsion shaft FP hydraulic pump

Claims (4)

[Claims] 1. A power transmission case having a transmission shaft driven by engine power is hung on a vehicle body frame on one of front and rear sides of an axle case that pivotally supports a pair of steering wheels.
The axle case or the power transmission case is provided with a hollow cylindrical center pivot portion X having a front-rear axis, and the axle case and the power transmission case are connected to each other via the center pivot portion X so that the axle case is rotated around the center pivot portion X. The first PTO shaft is supported on the other side of the axle case and the power transmission case driven by the engine power is provided in the power transmission case. A power take-out device for a work vehicle, characterized in that the power take-out device is inserted through a hole and is interlockingly connected to the first PTO shaft. 2. The power take-off device for a work vehicle according to claim 1, wherein a propulsion shaft for driving the steering wheel provided in the axle case and the first PTO shaft are arranged side by side in the vehicle width direction. A power take-out device for a work vehicle, which is characterized in that 3. The power take-off device for a work vehicle according to claim 1, wherein the power transmission case is integrally configured with a hydraulic pressure supply device including a hydraulic pump for driving a hydraulic actuator with the lubricating oil in the case. A power take-out device for a work vehicle characterized by the above. 4. The power take-off device for a work vehicle according to claim 1, wherein the power transmission case is equipped with a second PTO shaft driven by receiving engine power. .