JPS6137898Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a self-propelled working vehicle for agricultural use or other purposes, and has hydraulic equipment such as multiple hydraulic clutches in a hydraulic clutch type driving power transmission device in the driving force transmission path. In a self-propelled work vehicle that is equipped with hydraulic equipment such as a PTO clutch configured as a hydraulic clutch or multiple hydraulic clutches in a hydraulic clutch-type work machine power transmission system in the machine drive power transmission path, The present invention relates to a hydraulic pressure supply device for supplying operating hydraulic pressure to hydraulic equipment in a transmission path and hydraulic equipment provided in a working machine drive force transmission path.

That is, this invention is an attempt to provide a novel hydraulic pressure supply device for a self-propelled work vehicle, which is the above-mentioned hydraulic pressure supply device and has a simplified structure of the hydraulic pressure supply mechanism as much as possible.

Regarding the illustrated embodiment, the configuration of the hydraulic pressure supply system according to the invention will be described. As shown in FIG. The engine 3 is mounted on the tower, and the transmission case 4, which constitutes a part of the fuselage frame, is installed directly behind the engine 3.
The power is transmitted to the left and right rear wheels 2 through the transmission case 4, and also to the left and right front wheels 1 as necessary to cause the machine to travel. It is a self-propelled work vehicle that can be taken out as shown in the figure, and a passenger seat 5 is installed on the other side of the front part of the machine, and the operator sitting in the passenger seat controls the steering of the machine using the control handle 6. This invention is implemented as follows in a self-propelled working vehicle configured to swing the left and right front wheels 1.

That is, as shown in FIGS. 2 and 3, in the mission case 4 there are concentrically arranged
1A axis 11A, 1B axis 11B, and 2nd axis 12
, the third axis 13 , the fourth axis 14 , and the fifth axis 15
, the sixth axis 16, and the seventh axis 17 are provided parallel to each other. The first A shaft 11A is configured as a transmission input shaft, and is connected to the engine 3 outside the transmission case 4 by a coupling 21. The seventh shaft 17 is configured as a shaft for extracting running power, and is constantly connected to the left and right rear wheels in two directions at the rear end side, and is connected in one direction to the left and right front wheels at the front part of the seventh shaft 17. A front wheel drive force extraction shaft 19 that is constantly interlocked and connected is provided so as to straddle the inside and outside of the transmission case 4.
9 through a front wheel drive power clutch 22. In addition, the 1st B axis 11B is configured as a PTO axis for driving a hydraulic pump for various work machines (pump P shown in chain lines in FIG. For driving a chemical solution pump when the illustrated work vehicle is used as a speed sprayer with a chemical solution tank 23 mounted on the tower, or a pest control machine when various other pest control machines are attached to the illustrated work vehicle. It is constructed on the PTO shaft and extends rearward from the transmission case 4 as shown in FIGS. 1 and 2. Furthermore, the sixth shaft 16 is configured as a PTO shaft for driving various types of work equipment when the rear of the illustrated work vehicle is towed to perform plowing or other work, and is used as a PTO shaft to drive the work equipment following the transmission case 4. Airframe frame 24
(Fig. 1) is connected to a power take-off shaft 25 provided inside the frame 24 and extending rearward from the frame 24 by a coupling 26, and a working machine such as a snow blower is attached to the front of the illustrated working vehicle. to drive the snow removal machine, etc. when performing snow removal work.
It is configured as a PTO shaft and extends forward from the transmission case 4, as shown in FIG.

The seventh shaft 17 is interlocked with the first A-shaft via a main transmission 27 for driving power and a sub-transmission 28, of which the main transmission 27 located on the front side is a hydraulic clutch type. The transmission is configured with three gears in the forward direction and one gear in the reverse direction, as will be described in detail later, and correspondingly includes four hydraulic clutches 29F ₁ , 29F ₂ , 29F ₃ , 29
It is equipped with R. On the other hand, the 1st B shaft 11B is configured as a multi-plate hydraulic clutch with respect to the 1st A shaft 11A.
They are operatively connected via a PTO clutch 30. In the illustrated case, the hydraulic supply device according to this invention includes the hydraulic clutches 29F ₁ , 29F ₂ , 29F ₃ , 29R provided in the travel driving force transmission path and the PTO provided in the working machine driving force transmission path.
The clutch 30 is configured as follows for supplying hydraulic pressure.

That is, as shown in FIG. 2, the 1A axis 11A
At the top, there is a hydraulic pump 3 driven by the shaft 11A.
As shown in FIG. 4, this hydraulic pump 31 is equipped with hydraulic clutches 29F ₁ , 29F ₂ ,
A common hydraulic pump is configured to supply hydraulic oil to 29F ₃ , 29R and the PTO clutch 30 from an oil tank 32. This hydraulic pump 3
Similarly, on the secondary side of 1, as shown in FIG.
A flow control valve configured by combining a relief valve (separate valve) 36 inserted into the valve 5 and a relief valve (separate valve) 36 that acts as a back pressure with the hydraulic pressure of the main circuit 33 on the downstream side of the throttle 34. 37 is provided. And in the case shown, the surplus flow circuit 35
Hydraulic clutch 29F ₁ , 29F ₂ , 29F ₃ , 29
The end of the surplus flow circuit 35 is connected to the primary side pump port of a first switching valve 38 that is configured as an oil supply circuit for the hydraulic clutches 29F ₁ , 29F ₂ , 29F ₃ , and 29R and that switches and controls the supply and discharge of hydraulic oil to the hydraulic clutches 29F 1 , 29F 2 , 29F 3 , and 29R. At the same time, the main circuit 33 is configured as an oil supply circuit for the PTO clutch 30, and the main circuit 33 is connected to the PTO clutch 30.
The end of the mainstream circuit 33 is connected to the primary side pump port of a second switching valve 39 that switches and controls the supply and discharge of hydraulic oil to and from the pump. The first switching valve 38 has one tank port in addition to the pump port on the primary side.
In addition, hydraulic clutches 29F ₁ , 29F ₂ , 2 are installed on the secondary side.
Oil supply and drainage circuit 40F ₁ to 9F ₃ and 29R, respectively.
40F ₂ , 40F ₃ , 40R, respectively, are provided with four clutch ports connected to each other through a surplus flow circuit 35 and a full oil supply/discharge circuit 40F ₁ , 40F ₂ , 4
Connect 0F ₃ and 40R to the oil tank 32,
Full hydraulic clutch 29F ₁ , 29F ₂ , 29F ₃ , 29
Neutral position N with R inactive and surplus flow circuit 35
Any one oil supply/drainage circuit 40F ₁ , 40F ₂ , 4
0F ₃ or 40R, and connects three other oil supply/drainage circuits to the oil tank 32 to selectively operate any one of the hydraulic clutches 29F ₁ , 29F ₂ , 29F ₃ or 29R 4 It has three working positions F ₁ , F ₂ , F ₃ , and R. Also the second
The switching valve 39 has one tank port in addition to the above-mentioned pump port on the primary side, and a clutch port connected to the PTO clutch 30 via an oil supply/drainage circuit 41 and a merging circuit 46 (described later) on the secondary side. The main circuit 33 is connected to the merging circuit 46 and the oil supply/drainage circuit 41 is connected to the oil tank 32.
It has a neutral position N in which the PTO clutch 30 is disengaged, and an operating position I in which the main circuit 33 is connected to the oil supply/discharge circuit 41 and the PTO clutch 30 is disengaged.

Similarly, as shown in FIG.
The respective hydraulic clutches 40F ₁ , 40F ₂ , 40 correspond to the case where the hydraulic clutches 40F ₁ , 40F ₂ , 40 are moved to the respective operating positions F 1 , F 2 , F ₃ , R
In order to set the hydraulic pressure applied to F ₃ , 40R, a first primary pressure regulating valve 43 is inserted into a first relief circuit 42 branched from the middle of the surplus flow circuit 35, and a first primary pressure regulating valve 43 is provided. 2 switching valve 39
When PTO clutch 30 is moved to working position I,
To set the hydraulic pressure applied to
A second primary pressure regulating valve 45 is inserted into a second relief circuit 44 branched from the middle of the mainstream circuit 33. In the illustrated case, each of these primary pressure regulating valves 43, 45 has springs 43a, 4 for setting the pressure.
The ends of 5a are received by pistons 43b and 45b that can move forward to a regulated position, and the pistons 43
By guiding the hydraulic pressure on the primary side of the pressure regulating valves 43, 45 behind the pressure regulating valves 43, 45b through the throttles 43c, 45c, when the switching valves 38, 39 are moved from the neutral position N to the operating position, the pistons 43b, 45b is gradually advanced and the clutch working oil pressure is gradually increased to the normal oil pressure so that shock-free clutch engagement is obtained. Also, especially
First relief circuit 42 and second relief circuit 4
4 are merged as shown in the figure on the secondary side of the primary pressure regulating barriers 43 and 45, and this merge circuit 46
is equipped with a single secondary pressure regulating valve 47 for setting the lubricating oil pressure, and this secondary pressure regulating valve 47
On the primary side, a lubricating oil supply circuit 48 supplies lubricating oil from the merging circuit 46 to lubricated parts such as the friction element parts of the hydraulic clutches 29F ₁ , 29F ₂ , 29F ₃ , 29R and the friction element part of the PTO clutch 30. , has been derived. The single-acting hydraulic cylinder 49 shown in FIG. 4 brakes the secondary side of the PTO clutch 30 to prevent inertial rotation when the PTO clutch 30 is disengaged, and the brake 5 shown in FIG.
This is to activate and release the brake on the 0.
As shown in FIG.
It is provided with a disk 53 supported non-rotatably by a rotation support metal fitting 52 to which a key 51 is fixed to the 1B shaft 11B, and a brake plate 54 facing a part of one surface of the disk 53. The hydraulic cylinder 49 is configured to actuate the braking action of the brake 50 by the action of a spring 49b when the hydraulic pressure is released from the oil chamber 49a, and when the PTO clutch 30 is engaged, the braking of the brake 50 is released. The oil supply/discharge circuit 41 is connected to the oil chamber 49a by a connection circuit 55 so that the brake 50 operates in the off state.

As described above, the first and second switching valves 38 and 39, the first and second primary pressure regulating valves 43 and 45, and the flow rate control valve 37 shown in FIG. It is located. That is, FIG. 5 shows a valve housing 56 installed on the mission case 4, and as shown in FIG. The second primary pressure regulating valves 43 and 45 are parallel to each other, with the first switching valve 38 and the first primary pressure regulating valve 43 being adjacent to each other, and the second switching valve 39 and the second primary pressure regulating valve 45 being adjacent to each other. In the case shown, the switching valves 38 and 39 are placed on both sides, and the primary pressure regulating valve 4 is placed on both sides.
3 and 45 are placed in the center. Further, on the upper surface of the valve housing 56, a valve case 57, which is shown taken out in FIG. 6, is installed along the rear end side of the valve housing 56 in the lateral direction as shown by the chain line in FIG. , the flow rate control valve 37 is placed inside the valve case 57, and the switching valves 38, 39 are placed inside the valve case 57.
and are provided along the direction orthogonal to the primary pressure regulating valves 43 and 45.

As shown in FIGS. 5 and 6, the valve housing 5
6 is formed with an oil passage 58 that is connected to the discharge port of the hydraulic pump 31.
is an oil passage 59 in the valve case 57 and is connected to an oil passage 59 that communicates with a pump port 61 formed in the valve case 60 of the flow rate control valve 37. In addition to the pump port 61, the valve case 60 has a main flow discharge port 62 and a surplus flow discharge port 63 formed at the positions shown in FIG. 6, respectively. Similarly, as shown in FIG. 6, a valve body 65 is provided inside the valve case 60 and is biased to move in one direction by a compression spring 64.
A plug 66 is inserted and installed. A portion of the oil flowing into the pump port 61 flows out from the mainstream discharge port 62 through the hollow valve body 65 and the throttle 34 in the plug 66. Hydraulic pressure acts on the valve body 65 as back pressure. The valve body 65 constitutes the valve body of the relief valve 36, and when it is moved back by a distance D or more shown in FIG. 6 against the force of the compression spring 64 and the back pressure, the valve body 65 closes the pump port 61. A window hole 65a that communicates with the surplus flow discharge port 63 through the hollow part of the valve body 65 is provided.
We are prepared. The other part of the oil flowing into the pump port 61 is caused to flow out from the surplus flow discharge port 63 when the valve body 65 is retracted as described above. The flow rate control valve 37 controls the pump 31 due to fluctuations in engine speed, etc.
Fluctuations in oil flow due to increases and decreases in rotational speed are caused by fluctuations in the oil pressure difference between the front and back surfaces of the valve body 65, causing the valve body 65 to vibrate back and forth, and when the amount of oil discharged from the pump 31 is large, the surplus flow discharge port Flow rate control is performed by increasing the amount of oil flowing out from the surplus flow discharge port 63, and decreasing the amount of oil flowing out from the surplus flow discharge port 63 when the amount of oil discharged from the pump 31 is small.

As shown in FIG. 5, the first switching valve 38 includes a spool 67. As shown in FIG. A proper position in the valve hole into which this spool 67 is inserted is communicated with the surplus flow discharge port 63 of the flow control valve 37 via an oil passage 68 in the valve case 57 and an oil passage 69 in the valve housing 56. The pump port 70P is opened. Further, in the same valve hole, each of the hydraulic clutches 29F ₁ , 29 in the main transmission 27 is provided.
Clutch ports 70F ₁ , 70F ₂ , 70F ₃ , which communicate with F ₂ , 29F ₃ , and 29R, respectively.
70R, and a plurality of tank ports 70T ₁ , 7 each communicating with the oil tank 32 configured at the lower part of the transmission case 4.
0T ₂ , 70T ₃ and 70T ₄ are also opened. The first switching valve 38 is caused to slide the spool 67 by its operating mechanism 67A, and appropriately connects and shuts off the ports 70, thereby performing circuit switching control as described above.

As shown in FIG. 5, the second switching valve 39 includes a spool 71. As shown in FIG. An oil passage 72 in the valve case 57 and an oil passage 7 in the valve housing 56 are connected to the main flow discharge port 62 of the flow rate control valve 37 at appropriate positions in the valve hole into which the spool 71 is inserted.
Pump port 74P communicated via 3
is left open. The same valve hole also has the above-mentioned
A clutch port 74C that communicates with the inside of the PTO clutch 30, a tank port 74T that communicates with the inside of the oil tank 32, and the secondary pressure regulating valve 4.
Drain port 74D leading in seven directions,
Each is left open. The second switching valve 38 is
The spool 71 is slid by the operating mechanism 71A, and the ports 74 are communicated and disconnected as appropriate to perform the circuit switching as described above.

Similarly, as shown in FIG.
3 and 45 are configured such that their valve bodies 43d and 45d are biased backward by springs 43a and 45a whose ends are received by pistons 43b and 45b as described above. Each primary pressure regulating valve 4
Valve cases 3 and 45 are connected to pump ports 43e and 4
5e, and drain ports 43f, 45f leading to the secondary pressure regulating valve 47, and the piston 43 of each primary pressure regulating valve 43, 45.
The apertures 43c and 45c, which are formed with small-diameter oil holes formed in the valve case, are opened behind b and 45b. The pump port 43e of the first primary pressure regulating valve 43 is communicated with the surplus flow discharge port 63 of the flow rate control valve 37 via an oil passage 75 in the valve case 57 and an oil passage 76 in the valve housing 56, Further, the pump port 45e of the second primary pressure regulating valve 45 is communicated with the mainstream discharge port 62 of the flow rate control valve 37 via an oil passage 72 in the valve case 57 and an oil passage 77 in the valve housing 56. . Each valve element 43d, 45d is provided with an oil hole 43g, 45g which connects the pump port 43e, 45e to the back of the valve element 43d, 45d. With the hydraulic pressure of the pump ports 43e, 45e, the valve bodies 43d, 45d close the pump port 43.
By moving forward to a position where e and 45e are communicated with drain ports 43f and 45f, each primary pressure regulating valve 43 and 45 performs a relief operation. The throttle 43c of the first primary pressure regulating valve 43 connects to the surplus flow discharge port 63 of the flow rate control valve 37, an oil passage 68 in the valve case 57, an oil passage 69 in the valve housing 56,
78, and the throttle 45c of the second primary pressure regulating valve 45 communicates with the mainstream discharge port 62 of the flow rate control valve 37, the oil passage 72 in the valve case 57, and the oil passage 7 in the valve housing 56.
3 and 79. In this way, the throttles 43c, 45c are placed behind the pistons 43b, 45b that receive the ends of the springs 43a, 45a.
The effect obtained by applying the primary side oil pressure of the primary pressure regulating valve 45 through the pressure regulating valve 45 is as described above with reference to FIG.

To explain the traveling driving force transmission mechanism provided in the transmission case 4, as shown in FIGS. 12, and the latter gear 81 is meshed with a gear 82 fixed to the third shaft 13, so that the third shaft 13 is always interlocked with the first A shaft 11A. It is connected. The main transmission 27 described above has the fourth shaft 1
The fourth and fifth shafts 15 are respectively configured as power shift shafts to form a hydraulic clutch type transmission as described above, and an idler gear 83F ₂ for forward second speed.
and the free rotating gear 83F ₃ for forward 3rd speed are connected to the fourth shaft 14.
An idler gear 83 for the first forward speed is provided on the top.
F ₁ and the free rotating gear 83R for reverse 1st speed are connected to the 5th shaft 1
It is located above 5. Of these, idle gear 83F ₁
and idling gear 83F ₂ are each meshed with a gear 84 fixed to the third shaft 13, and idling gear 83F ₃ is meshed with a gear 85 fixed to the third shaft 13, Furthermore, the free rotating gear 83R is provided to be freely rotatable on a support shaft 18 supported by the transmission case 4, and meshes with an R intermediate gear 86 that is meshed with the gear 82 on the third shaft 13. There is. On the fourth shaft 14 and the fifth shaft 15, the hydraulic clutches 29F ₁ , 29F ₂ , 29F ₃ , 29R are disposed on the free rotating gears 83F ₁ , 83F ₂ , 83F ₃ , 83R.
A friction element for a plurality of sheets is attached to the clutch housing 29a fixed to the fourth shaft 14 or the fifth shaft 15 and each free rotating gear 83F ₁ , 83F ₂ , 83F ₃ , 83R, respectively. Each of the hydraulic clutches 29F ₁ , 29F ₂ , 29F ₃ , 29R, which are freely supported and configured as a multi-plate type, can selectively operate the idler gears 83F ₁ , 83F ₂ , 83F ₃ or 83R is selectively coupled to the shaft 15 or 14 on which it is mounted. Both hydraulic clutches 29F ₂ , 2 are connected to the fourth shaft 14.
The output gear 88 is connected between 9F ₃ and the output gear 88 is connected to the fifth shaft 15 between both hydraulic clutches 29F ₁ and 29R.
9 are fixed respectively, and both the former output gear 88 having a larger diameter and the latter output gear 89 having a smaller diameter are large diameter gears loosely fitted to the sixth shaft 16. The gears 90 are meshed with each other. 6th
A small-diameter gear 91 that shares a common boss with the gear 90 is loosely fitted onto the shaft 16.
The shaft 17 has two gears 90, 9 on the sixth shaft 16.
2 having a common boss portion that can be meshed with 1 respectively
Shift gears 92 and 93 are spline-fitted and slidably provided, and the combination of gears 90 and 91 and shift gears 92 and 93 constitutes the sub-transmission device 28. Based on the above,
Each hydraulic clutch 29 in the main transmission 27
By selectively operating F ₁ , 29F ₂ , 29F ₃ or 26R, a gear ratio of 1st forward speed, 2nd forward speed, 3rd forward speed or 1st reverse speed can be selectively obtained. By selectively meshing gears 91 and 93, the gear ratio of 1st speed, gears 90, 9
By selectively engaging the gears 2 and 2, the gear ratios of the 2nd speeds can be selectively obtained, and the seventh shaft 17 can be rotated at appropriate speeds.

Further, the working machine driving force transmission mechanism within the mission case 4 is configured as follows. That is,
As shown in FIGS. 2 and 3b, first, the small diameter gear 94 fixedly provided on the 1B shaft 11B is
2, meshing with the large diameter gear 95 fixedly provided on the
The 1B shaft 11B is connected to the second shaft 12 for deceleration. Further, a gear 96 fixed to the second shaft 12 meshes with a gear 97 loosely fitted to the third shaft 13, and the latter gear 97 is fixed to the sixth shaft 16 and meshes with a gear 98. The second shaft 12 is connected to the sixth shaft 16 in a deceleration manner by meshing with the sixth shaft 16. That is,
1st B axis 11B, which functions as PTO axis, 2nd axis 1
The second and sixth shafts 16 are always interlocked and connected.

As shown in FIG. 2, the PTO clutch 30
This is a multi-plate hydraulic clutch in which one and the other friction elements are supported by a clutch housing 100 which is fixed to the first A shaft 11A by a key 99 and by the rotation support hardware 52.
In FIG. 2, reference numeral 101 denotes a brake disposed on the fifth shaft 15, and this brake 101 is configured to perform a braking action using the force of a spring 101a, perform a braking action using hydraulic pressure, and release the braking action. As shown in FIG. 4, the oil pressure of the surplus flow circuit 35 is guided to the oil chamber 101b by a connection circuit 102. Therefore, this brake 101
When the main transmission 27 is in the transmission state, the oil pressure of the surplus flow circuit 35 is applied so that no braking action is performed, and the first switching valve 38 is moved to the neutral position N, so that the main transmission 27 is also in the neutral state. When the spring 101a is activated, the fifth shaft 15 is connected to the fifth shaft 15, and the sixth shaft 1, which is always connected to the fifth shaft 15, is
6. The seventh shaft 17 and the fourth shaft 14 are also braked, and the rotational torque acting on the driving side of the main transmission 27 causes the hydraulic clutches 29F ₁ , 29F ₂ , 29F ₃ , 29
The R friction elements are engaged with each other with a slight engagement force, thereby preventing unexpected power transmission from the driving side to the driven side of the main transmission 27.

As is clear from the foregoing, the hydraulic pressure supply device for the self-propelled working vehicle of this invention has the first hydraulic device 29 provided in the traveling driving force transmission path.
A common hydraulic pump 31 is provided for supplying hydraulic oil to F ₁ , 29F ₂ , 29F ₃ , 29R and the second hydraulic equipment 30 provided in the working machine drive force transmission path, respectively, and this hydraulic pump A flow control valve 37 on the secondary side of 31 is provided, and the flow control valve 37
One of the main flow circuit 33 and the surplus flow circuit 35 is connected to the first hydraulic equipment 29F ₁ , 29F ₂ , 29
F ₃ , 29R, and the other is configured as an oil supply circuit for the second hydraulic equipment 30, and the first hydraulic equipment 29F ₁ , 29
A first switching valve 38 that controls supply and discharge of hydraulic oil to F ₂ , 29F ₃ , 29R, and a first adjustment valve that sets working oil pressure for the first hydraulic equipment 29F ₁ , 29F ₂ , 29F ₃ , 29R. A pressure valve 43, a second switching valve 39 that controls the supply and discharge of hydraulic oil to the second hydraulic device 30, and a second pressure regulating valve 45 that sets the working oil pressure to the second hydraulic device 30,
The first switching valve 38 and the first pressure regulating valve 43 are arranged adjacent to each other, the second switching valve 39 and the second pressure regulating valve 45 are arranged adjacently and parallel to each other, and the flow rate control valve 37 is The switching valves 38, 3 are located close to the switching valves 38, 39 and the pressure regulating valves 43, 45.
9 and the pressure regulating valves 43 and 45 in a direction perpendicular to each other.
It has the following advantages:

That is, the hydraulic supply device of this invention includes hydraulic equipment 29F ₁ ,
This is because a common hydraulic pump 31 supplies hydraulic pressure to 29F ₂ , 29F ₃ , 29R and the hydraulic equipment 30 provided in the working machine driving force transmission path using a flow control valve 37. , an expensive hydraulic pump is omitted, and the structure of the hydraulic pressure supply mechanism is simplified as much as possible. Moreover, the hydraulic supply device of this invention has the first and second
Hydraulic pump 31 that supplies hydraulic pressure to the hydraulic equipment of
A flow rate control valve 37 that is shared by a first switching valve and pressure regulating valve 38, 43 for the first hydraulic equipment and a second switching valve and pressure regulating valve 39, 45 for the second hydraulic equipment The four valves 3 are placed adjacent to each other.
8, 43, 39, 45 are arranged in parallel, and are located close to and perpendicular to these valves 38, 43, 39, 45, so that the four valves 3
By arranging the valves 8, 43, 39, and 45 in parallel, not only the valve part in the hydraulic pressure supply mechanism is made compact, but also one of the main flow discharge port 62 and the surplus outflow port 63 of the flow control valve 37 is used as a first switching valve. and pressure regulating valves 38 and 43, and the other is located close to the second switching valve and pressure regulating valves 39 and 45. between the switching valve and the pressure regulating valve (in the embodiment, the first switching valve and the pressure regulating valve 38, 43) to be connected to the oil passage between the second switching valve and the pressure regulating valve 39, 45) and the surplus flow discharge port 63; The oil passage can be made short and simple, and the oil passage structure can be simplified.

[Brief explanation of drawings]

Figure 1 is a schematic side view of a self-propelled working vehicle equipped with an embodiment of this invention, Figure 2 is a longitudinal side exploded view of the main parts of the working vehicle, and Figures 3a and 3b are respectively shown in Figure 2. 4 is a schematic front view showing the arrangement of the transmission shaft and gears in the illustrated part, FIG. 4 is a circuit diagram showing the hydraulic circuit of the same embodiment, and FIG. 5 is a cross-sectional plan view of the main part of the same embodiment.
FIG. 6 is a cross-sectional plan view of other essential parts of the same embodiment. 1...front wheel, 2...rear wheel, 3...engine, 4
...Mission case, 11A...1st A axis, 1
1B...1B axis, 12...2nd axis, 13...3rd axis, 14...4th axis, 15...5th axis, 16...
...6th axis, 17...7th axis, 27... Main transmission, 28... Sub-transmission, 29F ₁ , 29F ₂ , 2
9F ₃ , 29R...Hydraulic clutch, 30...PTO
Clutch, 31... Hydraulic pump, 32... Oil tank, 33... Mainstream circuit, 34... Throttle, 35...
Surplus flow circuit, 36...Relief valve (divider valve), 3
7...Flow control valve, 38...First switching valve, 39
...Second switching valve, 40F ₁ , 40F ₂ , 40F ₃ ,
40R... Oil supply and drainage circuit, 41... Oil supply and drainage circuit, 4
2...First relief circuit, 43...First primary pressure regulating valve, 44...Second relief circuit, 45...
Second primary pressure regulating valve, 56...valve housing,
57... Valve case, 58, 59... Oil passage,
60...Valve case, 61...Pump port, 62
... Mainstream discharge port, 63 ... Surplus flow discharge port, 64 ... Compression spring, 65 ... Valve body, 66 ...
Plug, 67...Spool, 68, 69...Oil passage, 70P...Pump port, 70F ₁ , 70
F ₂ , 70F ₃ , 70R...Clutch port, 70
T ₁ , 70T ₂ , 70T ₃ , 70T ₄ ... Tank port, 71 ... Spool, 72, 73 ... Oil passage,
74P...Pump port, 74C...Clutch port, 74T...Tank port, 74D...Drain port, 43a, 45a...Spring, 43
b, 45b... Piston, 43c, 45c... Throttle, 43d, 45d... Valve body, 43e, 45e...
...Pump port, 43f, 45f...Drain port, 43g, 45g...Valve body, 75, 76, 7
7, 78, 79...Oil passage.

Claims (1)

[Scope of utility model registration request] A first hydraulic device provided in the traveling driving force transmission path and a second hydraulic device provided in the working machine driving force transmission path.
A common hydraulic pump is provided for supplying hydraulic oil to each of the hydraulic equipment, and a flow rate control valve is provided on the secondary side of this hydraulic pump, and a flow rate control valve is provided between the main flow circuit and the surplus flow circuit of the flow control valve. one of which is configured as an oil supply circuit for the first hydraulic equipment, and the other is configured as an oil supply circuit for the second hydraulic equipment, and a first controller that controls supply and discharge of hydraulic oil to and from the first hydraulic equipment. a switching valve; a first pressure regulating valve that sets the working oil pressure for the first hydraulic device;
A second switching valve that controls the supply and discharge of hydraulic oil to the second hydraulic equipment, and a second pressure regulating valve that sets the working oil pressure for the second hydraulic equipment, are connected to the first switching valve and the first switching valve. The pressure regulating valves are arranged adjacent to each other, and the second switching valve and the second pressure regulating valve are arranged adjacently and parallel to each other, and the flow rate control valve is located close to these switching valves and the pressure regulating valve, and the switching valve is arranged in parallel to each other. and a hydraulic pressure supply device for a self-propelled working vehicle, characterized in that it is provided along a direction perpendicular to the pressure regulating valve.