JPS638493Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention comprises a gear transmission housed in a case, a shift rod connecting shift forks of the gear transmission, and a shift rod connected to both ends of the shift rod. a hydraulic cylinder for operating the gear transmission, a clutch operation valve of a hydraulic clutch for the gear transmission, and a gear shift valve for operating the fluid pressure cylinder, the gear transmission valve, the fluid pressure cylinder, and the clutch operating valve. The present invention relates to a transmission device for a work vehicle, which is configured to be connected to a valve so that the hydraulic cylinder and the hydraulic clutch are actuated by the working fluid supplied through the variable speed valve.

The above-mentioned transmission device for the work vehicle performs gear shifts based on the operation of a shift valve, and also enables the operation of a hydraulic clutch based on the operation of the shift valve, making the shift operation easy and less likely to be erroneous. This method allows the user to perform the task in the state of
A shift rod equipped with a fluid pressure cylinder for operating a shift fork, a clutch operation valve for a hydraulic clutch, and a transmission valve for operating the fluid pressure cylinder are each manufactured as separate parts, and these shift rods, clutch operation valves, and transmission valves are manufactured as separate parts. Each piece was attached to the transmission case separately and connected to each other by piping, which required time and effort to manufacture and assemble, and the structure of the transmission device became complicated, requiring time and effort during inspection and maintenance. There was a problem with the overall size.

The present invention has been made in view of the above-mentioned circumstances, and is based on these shift rods, clutch operation valves,
By focusing on the fact that the variable speed valves are assembled into the transmission case in close relation to each other, and by devising the assembly structure, we have simplified the overall structure of the device and made manufacturing and assembly easier. At the same time, the purpose is to miniaturize the entire device so that it can be easily installed even in a narrow space.

The characteristic configuration of the present invention for achieving the above object is that in the above-mentioned transmission device for a work vehicle, a through hole is formed in the side wall of the case, and the cylinder tube of the fluid pressure cylinder and the valve casing of the speed change valve are connected to each other. is opened at the inner peripheral surface of the through hole and integrally cast within the thickness of the side wall, and the shift rod and the spool of the speed change valve are arranged in a position to cross the through hole along the wall surface of the side wall. A plate configured to support the side wall, tightly fixing a lid body made of a plurality of overlapping plate-like bodies to the outer surface of the side wall to close the through hole, and forming the outermost surface of the lid body. The valve casing of the clutch operation valve is integrally cast in the shape body, and a connecting flow path connecting the speed change valve, the fluid pressure cylinder, and the clutch operation valve is formed between the plurality of plate bodies constituting the lid body. It is formed on the mating surface, and this structure provides the following effects.

i.e. a shift rod with a hydraulic cylinder;
Instead of manufacturing the speed change valve and clutch operation valve separately and assembling them into the transmission case,
A through hole is formed in the side wall of the transmission case, and the cylinder tube and the valve casing of the speed change valve are integrally cast within the wall thickness of the side wall with the cylinder tube and the valve casing of the speed change valve opening on the inner peripheral surface of the through hole, and the shift rod and the speed change valve are integrally cast together within the thickness of the side wall. The casing of the clutch operation valve is integrally cast on a lid body that is closely fixed to the side wall in order to close the through hole, and the lid body is attached to a plurality of plates. A connection passage connecting the fluid pressure cylinder, speed change valve, and clutch operation valve to each other is formed on the mating surface of the plate body, and connection piping is installed, which is complicated in shape and requires time to manufacture. This eliminates the disadvantages of manufacturing the device, which reduces the number of parts and simplifies the overall structure of the device, making it easier to manufacture and assemble.

Moreover, the fluid pressure cylinder and the speed change valve are configured to be mounted compactly by using the side wall of the transmission case in a position along the wall surface of the side wall, and the lid body on which the clutch operation valve is integrally cast is effectively utilized. Since the fluid pressure cylinder, the speed change valve, and the clutch operation valve are connected compactly by the shortest distance, the entire device can be downsized.

Therefore, the entire transmission device can be manufactured at low cost and can be easily installed in a narrow space.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in Fig. 1, a driving shaft 2 is linked to the engine 1, a main gear transmission M 1 that can switch in four stages is linked to the driving shaft 2, and a main gear transmission M ₁ is attached to the output shaft 3 of the transmission M ₁ . A hydraulic clutch 4 as an example of a fluid pressure clutch is connected to a transmission case 5.
Internally equipped with a forward/reverse switching gear transmission M ₂ , an auxiliary gear transmission M ₃ that can be switched to two high and low speeds,
Reduction transmission M ₄ , which can be switched to non-reduction state,
In this order, the hydraulic clutch 4 is interlocked with the output side and installed in the transmission case 6, and the first output shaft 7 of the reduction transmission _M4 is interlocked with the differential mechanism 9 of the rear wheel 8. , and the first
The second output shaft 11 provided in the reduction mechanism _M4 is interlocked with the output shaft 7 through the clutch gear 10, and is interlocked with the differential mechanism 13 of the front wheels 12, thereby changing the speed for driving the agricultural tractor. The device has been configured.

A four-stage switchable gear transmission M ₅ linked to the drive shaft 2 and a hydraulic clutch 15 attached to the output shaft 14 of this gear transmission are housed in the transmission case 5, and the hydraulic clutch 15
The output side of the working device is linked to a power take-off shaft 46 for the connected working device to constitute a working device transmission device.

The operating structure of the traveling transmission device is constructed as follows.

i.e. main gear transmission M ₁ of 2
The shift forks 16 and 17 are configured to be operated by a hydraulic cylinder 18 or 19 as an example of a fluid pressure cylinder, and the shift fork 20 of the auxiliary gear transmission _M3 is configured to be operated by a hydraulic cylinder 21. configure, and
The three cylinders 18, 19, 21 are driven by lubricating oil in the transmission case 5 supplied as hydraulic oil by a pump 22 configured to be driven by the driving shaft 2. By means of one rotary manually operated speed change valve 23, which is provided with eight transmission positions so as to express eight transmission states obtained by the combination of the main and sub-missions _M1 and _M3 . 3 cylinders 18, 19,
21 to operate both the main and sub-missions M ₁ and M ₃ .

As shown in FIGS. 2 and 3, a through hole 6b is formed in the side wall 6a of the mission case 6, and a shift fork 25 for operating the switching gear 24 is connected to the shift rod 25a. Pistons 27 formed at both ends
A hydraulic cylinder 28, which is an example of a fluid pressure cylinder, is fitted into a cylinder tube 26 which is integrally cast within the thickness of the side wall 6a of the transmission case 6 in a state where it opens at the inner circumferential surface of the through hole 6b.
As shown in FIGS. 2 and 4, the shift fork 25 is configured to be operated by the cylinder tube 26, and the shift fork 25 is opened in the inner circumferential surface of the through hole 6b in the same way as the cylinder tube 26. A spool 30 is slidably fitted into a valve casing 29 that is integrally cast within the thickness of the side wall 6a of the transmission case 6, thereby forming a forward/reverse switching valve 31 as an example of a speed change valve. As shown in FIGS. 4 to 4, two plate-like bodies 32a and 32b are formed with groove-shaped channels on their mating surfaces, and both plate-like bodies 3 are sandwiched between these plate-like bodies 32a and 32b.
A single plate-like body 32c configured to isolate the flow paths of the two plate-like bodies 32a and 32b and provided with a through hole for communicating the flow paths of both the plate-like bodies 32a and 32b.
The input port 28a of the cylinder 28 and the output port 31a of the valve 31,
31a, and a portion 34a formed in the side walls of the transmission case 5 and transmission case 6, respectively, of the connection flow paths between the input port 31b of the valve 31 and the pump 22;
constitutes a lid body 32 forming a portion 34b excluding
The lid body 32 is closely fixed to the outer surface of the side wall 6a to close the through hole 6b, and the cylinder 28 and the valve 31, and the valve 31 and the pump 22 are shown in FIG. Connect the valve 31 to the swinging fork 35a.
The forward/reverse switching transmission _M3 is manually operated via a lever 35.

As shown in FIGS. 2 and 3, the lid 32
A spool 37 is slidably fitted into a valve casing 36 that is integrally cast on the plate-like body 32b that constitutes the outermost surface of the plate-like bodies 32a, 32b, and 32c that constitute the hydraulic clutch 4. As shown in FIG. Flow path 40 formed in 32
Accordingly, the sub-mission operation cylinder 21 has a flow path consisting of a flow path portion 41a formed in the lid body 32 and a flow path portion 41b formed in the side walls of the mission case 6 and the transmission case 5, respectively. 41 to the hydraulic clutch 4, so that hydraulic oil from the forward/reverse switching valve 28 is supplied to the hydraulic clutch 4 only when both the forward/reverse switching cylinder 28 and the auxiliary transmission operation cylinder 21 are in the transmission position. As shown in FIG.
b, and so that the hydraulic oil from the first operation valve 38 is automatically switched to the state of supplying the hydraulic clutch 4 only when the transmission valve 23 is in the transmission position. cylinder 1
8, 19, both main and sub-missions M ₁ ,
When at least one of M ₃ and the forward/reverse switching transmission M ₂ is in the neutral state, the hydraulic clutch 4 is disengaged, and both the main and auxiliary transmissions M ₁ , M ₃ and the forward/reverse switching transmission M ₂ are all in the transmission state. When this happens, the hydraulic clutch 4 is automatically engaged.

Rotary type variable speed valve 43 shown in Fig. 2
are for operating two hydraulic cylinders 44a and 44b that operate the power take-off shaft transmission _M5 . The operating valve 45 of the hydraulic clutch 15 is connected to the transmission valve 43 so that it is in the engaged position only when it is in the transmission position, and when the transmission _M5 is in the neutral state, the hydraulic clutch is engaged. 15 is in the disengaged state and the transmission _M5 is in the transmission state, the hydraulic clutch 15 is automatically switched to the engaged state.

The present invention is a gear transmission for various devices other than a gear transmission or a traveling device that switches only forward speed or reverse speed, such as the main gear transmission, auxiliary gear transmission, or power take-off shaft gear transmission. The forward/reverse switching transmission _M2 will be referred to as a gear transmission _M2 , and the forward/reverse switching valve 31 will be referred to as a shift valve 31.

Furthermore, the present invention can also be applied to various work vehicles such as combines, transport vehicles, and construction vehicles.

Note that although reference numerals are written in the claims section of the utility model registration for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.

[Brief explanation of the drawing]

The drawings show an embodiment of the transmission device for a working vehicle according to the present invention, and FIG. 1 is a schematic diagram of a traveling transmission device and a transmission device for a working device, FIG. 2 is an exploded perspective view of a plate-shaped body, and FIG. 3 4 is a sectional view of the shift fork operating cylinder, FIG. 4 is a sectional view of the forward/reverse switching valve, FIG. 5 is a sectional view of the clutch operating valve, and FIG. 6 is a hydraulic circuit diagram. 4...Clutch, 6...Mission case, 2
2...pump, 25...shift fork, 26...
...Cylinder tube, 28...Cylinder, 29,
36... Valve casing, 31... Speed change valve, 6a... Side wall, 6b... Through hole, 25a...
Shift rod, 30... Spool, 32... Lid body, 32a, 32b, 32c... Plate body, 33
a, 33b, 39...connection flow path, 38...clutch operation valve, _M2 ...gear transmission.

Claims (1)

[Scope of utility model registration request] Gear transmission inside case 6
M ₂ and a shift rod 25a connecting the shift fork 25 of the gear transmission M ₂
, a fluid pressure cylinder 28 connected to both ends of the shift rod 25a to operate the shift fork 25, and the gear transmission.
A clutch operating valve 38 of the fluid pressure clutch 4 for M ₂ and a speed change valve 31 for operating the fluid pressure cylinder 28 are provided, and the speed change valve 31, the fluid pressure cylinder 28, and the clutch operation valve are connected; The hydraulic cylinder 2 is controlled by the working fluid supplied through the speed change valve 31.
8 and the hydraulic clutch 4, a through hole 6b is formed in the side wall 6a of the case 6, and a through hole 6b is formed in the side wall 6a of the case 6, and the cylinder tube 26 of the hydraulic cylinder 28 and the transmission The valve casing 29 of the valve 31 is opened at the inner circumferential surface of the through hole 6b and is integrally cast within the thickness of the side wall 6a, so that the shift rod 25a
and the spool 30 of the speed change valve 31 are supported along the wall surface of the side wall 6a in a posture that traverses the through hole 6b, and a plurality of plate-like bodies 32a, 32b are provided on the outer surface of the side wall 6a. ，
The through hole 6b is closed by tightly fixing the lid body 32 formed by overlapping the two parts 32c, and the lid body 32 is closed.
The valve casing 36 of the clutch operating valve 38 is integrally cast on the plate-shaped body 32b constituting the outermost surface of the clutch operating valve 38, thereby forming a connecting flow path connecting the speed change bell 31, the fluid pressure cylinder 28, and the clutch operating valve 38. 33a, 33b, 39 are a plurality of plate-shaped bodies 32a, 32b, 3 constituting the lid body 32.
A transmission device for a work vehicle, characterized in that the transmission device is formed on a mating surface of 2c.