JP2007167035A - Hydraulic system for mobile farming machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a production cost by enabling each hydraulic control valve to have compatibility without preparing the hydraulic control valves by each specification when constituting tractors having different specifications. <P>SOLUTION: The tractor carrying out the steering control by the hydraulic oil of a hydraulic pump 2 driven by an engine 1 is constituted as follows. The first metal 5 including a main pressure-reducing valve 4 in the inside, the second metal 8 including a switching valve 7 controlling the switching of driving in four wheel drive, and the switching of acceleration of a front wheel in the inside, and the third metal 10 including a turning-control valve 9 in the inside are attached in piles to the side part of a transmission case 3 constituting a car body so as to be detachable one by one. An oil passage opened in the third metal 10 side of the second metal 8 can be closed by attaching a lid body 11 by removing the third metal 10 positioned at the outside. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydraulic apparatus for a mobile agricultural machine such as a tractor or a riding management machine, and relates to an arrangement configuration of a hydraulic control valve for controlling a piping of a steering hydraulic equipment and each hydraulic equipment used for them.

  The mobile farming machine makes two-wheel drive or four-wheel drive depending on the hardness and dryness of the working field, but depending on the driving state, the turning operation also increases the outer wheel of the turn or decelerates the inner turn. In addition to using the full turn that accelerates the front wheel side with respect to the rear wheel, the turning method suitable for the working field and the working state is selected. In addition, the cultivator is moved up and down at the same time as turning, but the speed of these wheels is increased and decreased by switching the control valve of the hydraulic equipment.

For this reason, mobile agricultural machines require many control valves for operation, and the hydraulic piping is complicated, making assembly work and inspection and maintenance at the time of failure difficult.
Therefore, the present applicant has a configuration in which complicated hydraulic piping is eliminated, and various control switching valves are provided centrally on one side of the mission case, and an oil passage serving as a pressure oil passage is provided inside the mission case. An application has already been filed (Japanese Patent Application Laid-Open No. 2004-201622).
JP 2004-201622 A

  In the configuration of the application, the hydraulic pipes that had been piped around the mission case were eliminated, and it was easy to check and replace control valves that were concentrated in one place. Because it was a dedicated part that was determined for each model, new parts had to be manufactured for models with different product specifications. Therefore, an object of the present invention is to reduce the manufacturing cost by making the control valve have a common structure so that it can cope with the specification change without making a dedicated part for each model.

The above object of the present invention is achieved by the following configuration.
That is, in the first aspect of the present invention, the main pressure reducing valve 4 is built in the side portion of the transmission case 3 constituting the vehicle body in the tractor that performs the steering control with the hydraulic oil of the hydraulic pump 2 driven by the engine 1. The first metal 5 and the second metal 8 containing the switching valve 7 for controlling the drive switching between the 2WD and the 4WD and the front wheel speed increase switching and the third metal 10 containing the turning brake valve 9 are sequentially attached in a detachable manner. The oil path opened to the third metal 10 side of the second metal 8 can be closed by removing the third metal 10 located outside and attaching the lid 11.

  In the second aspect of the present invention, the spacer metal 12 for connecting the front mission case 3a and the rear mission case 3b is provided at the position where the first metal 5 of the mission case 3 is installed in the configuration of the first aspect. 12, oil passages 55 and 57 of the switching valve 7 for controlling the turning braking valve 9 and the drive switching between the 2WD and 4WD and the front wheel speed increase switching are formed.

  Further, the invention described in claim 3 is characterized in that, in the configuration described in claim 2, the two-wheel drive / four-wheel drive switching and front wheel speed increasing hydraulic clutch 38 is disposed in the vicinity of the spacer metal 12.

  Since the present invention is configured as described above, in the invention described in claim 1, the main pressure reducing valve 4 provided in the first metal 8 at the first stage controls the pressure oil from the hydraulic pump 2 to be reduced to the optimum pressure, thereby The second metal 8 of the eye is provided with a switching valve 7 for driving switching between 2WD and 4WD and front wheel acceleration, thereby satisfying the basic function of the tractor. In other words, the tractor that can turn by driving switching between the 2WD and 4WD and speeding up the front wheels by mounting up to the second stage. Furthermore, when the third metal 10 at the third stage is attached, it can be changed to a high-grade tractor having a convenient function of reducing the turning radius by the turning brake valve 9.

  In the invention according to the second aspect, the formation of the oil passage for the two-wheel drive / four-wheel drive switching valve 6 and the front wheel speed-increasing valve 7 in the transmission case 3 is processed by processing a relatively small spacer metal 12. Since this can be done, the oil passage can be easily processed and the production cost can be reduced.

  Furthermore, in the invention according to claim 3, by arranging the two-wheel drive / four-wheel drive switching and front wheel speed increasing clutch 38 in the vicinity of the spacer metal 12, it is possible to reduce the pressure loss of the pressure oil as compared with the conventional one and turn response. You can make sex faster.

Hereinafter, an embodiment in which the present invention is implemented in an agricultural tractor will be described with reference to the drawings.
An embodiment of the present invention will be described with reference to the drawings.

  FIG. 3 shows a riding tractor. The engine 1 is mounted on the front portion of the tractor T, and the rotational power of the engine 1 is used as a main auxiliary transmission gear mechanism (main auxiliary transmission) 16 in the transmission case 3. , 17, and the rotational power decelerated by the main / sub transmissions 16, 17 is transmitted to the front wheels 18 and the rear wheels 19. A hydraulic cylinder case 20 is provided above the transmission case 3, and a lift arm 21 is pivotally attached to the hydraulic cylinder case 20. When the hydraulic oil is supplied into the hydraulic lift cylinder 22 in the hydraulic cylinder case 20, the lift arm 21 is turned up, and when it is discharged, the lift arm 21 is lowered.

  The lift arm 21 and the lower link 23 are connected by a lift rod 24, and a working machine such as a rotary attached to the lower link 23 moves up and down by the lift drive of the lift arm 21.

The steering handle 25 is configured to steer the left and right front wheels 18 to the left and right by turning left and right, and a driver seat 26 is provided behind the steering handle 25.
FIG. 4 is a power transmission path diagram of the tractor traveling system. The rotational power of the engine 1 is obtained by the main clutch 28 that is intermittently operated by the operation of the main clutch pedal 27, the four-speed transmission (the main transmission first speed to the fourth speed). Is transmitted to a main transmission 16 that can perform three-speed shifting at high, medium, and low speeds, and the main transmission 16 and the auxiliary transmission 17 The reduced rotational power is transmitted via the pinion bevel gear shaft 31 to the rear wheel differential device 32 provided at the rear of the transmission, and is transmitted to the rear wheel 19 via the final reduction gear mechanism.

  The drive shaft 33 extending from the rear wheel differential device 32 to the left and right is provided with a brake device including a brake disc 34 and a brake actuator 35, etc., and brakes are performed via the brake actuator 35 by operating the left and right brake pedals 36R and 36L. The disc 34 is crimped to brake the left rear wheel or the right rear wheel of the left and right rear wheels 19.

  Rotational power to the front wheels 18 branched from the pinion bevel gear shaft 31 is transmitted through a front wheel transmission shaft 37 and a two-wheel / four-wheel drive switching clutch 38 in the form of a multi-plate clutch (also used for front wheel acceleration as described later). The left and right front wheels 18 and 18 are driven by being transmitted to the front wheel differential device 39. Further, the PTO driving force is taken out via a PTO clutch and a PTO transmission (not shown), via a PTO transmission shaft 40, to a PTO shaft 41 protruding rearward from the back of the transmission mission case 3.

  FIG. 5 shows an example of the configuration of the main transmission (main transmission gear mechanism) 16 in the case of four-speed transmission. The main transmission gear mechanism 16 is a cylindrical counter provided coaxially with the pinion bevel gear shaft 31. A shaft 42 and an input transmission shaft 43 as a PTO transmission shaft are provided. Among these, the input transmission shaft 43 is provided integrally with the input gear 44, which will be described later, and a transmission shaft 45 having a wide clutch pawl 45a is rotatably fitted at a position away from the appropriate distance. The first and second speed transmission gears 46b and 47b are provided with clutch pawls 46a and 47a, respectively, and are loosely fitted to the transmission shaft 43. On the other hand, on the lower side of the wide clutch pawl 45a, a fourth speed transmission shaft 48b and a constantly meshing transmission shaft 49b provided with clutch pawls 48a and 49a are provided, respectively, and a third speed transmission shaft 49b, The fourth speed transmission shaft 48 is loosely fitted in order.

  The clutch pawls 46a, 47a, 48a and 49a provided before and after the clutch pawl 45a are all provided with the same diameter, and with the sliding of the main transmission clutch pawl 52 provided with two convex clutch portions, The rotation of the transmission shaft 43 can alternatively be transmitted to the first, second and fourth transmission gears 46b, 47b and 48b and the constantly transmitting gear 49b.

  On the other hand, on the counter shaft 42 side, a first speed counter gear 46c that meshes with the first speed gear 46b and a second speed counter gear 47c that meshes with the second speed gear 47b are integrally provided by spline fitting, respectively. A fourth speed counter gear 48 c and a transmission gear 49 c for transmitting the variable speed rotation of the counter shaft 42 to the auxiliary transmission counter shaft 53 are integrally formed on the rear end side of the cylindrical counter shaft 42.

  Accordingly, the transmission transmission rotation from “first speed” to “fourth speed” is applied to the counter shaft 42 by the selective sliding of the clutch pawl 52. For example, when one of the main transmission clutch 52 and the first speed clutch pawl 46a are engaged with each other, the rotation of the transmission shaft 45 is transmitted to the first speed transmission shaft 46, and the counter gear 46c is interlocked. Rotating at "speed".

The rotation of the counter shaft 42 is transmitted to the transmission gear 49c and the constantly meshing transmission gear 49c, and the auxiliary transmission counter shaft 53 integrated therewith is interlocked.
The “third speed” is performed by meshing one of the main transmission clutches 52 with the clutch pawl 49 a so that the rotation of the transmission shaft 45 is transmitted to the auxiliary transmission counter shaft 53 as it is.

  As described above, a pair of first-speed transmission gears 46b, 46c capable of meshing transmission, and a pair of two-speed transmission gears 47b, 47c capable of meshing transmission, and a pair of meshing transmission capable of meshing transmission. A clutch pawl 49a is extended to the shaft 43 side transmission gear 49b out of the constantly meshing transmission gears 49b and 49c provided on the way from the shaft 42 to the shaft 43. In addition, by engaging the clutch pawl 49a with the main transmission clutch pawl 52, a "third speed" gear stage can be obtained. In other words, the constantly meshing transmission gear 50 is configured so as to substitute for the “third speed” gear.

  Accordingly, the "first speed" gear stage is obtained by meshing the main transmission clutch pawl 52 and the first speed transmission gears 46b, 46c, and the "second speed" is achieved by meshing the main transmission clutch pawl 52 and the second speed transmission gear 47b. "Gear stage" is obtained, and further, the "fourth speed" gear stage is obtained by meshing the main gear clutch claw 52 and the fourth speed gear 48b, and the "third speed" gear stage is the main gear clutch. It is obtained by meshing of the pawl 52 with the clutch pawl 49 a of the constantly meshing gear transmission 49, and is transmitted to the auxiliary transmission counter shaft 53 from this.

  Rotational power from the engine 1 to the main transmission 16 is transmitted to the shaft 43 through the input transmission shaft 54, the input gear 44, and the transmission gear 45 that is always meshed with the input gear 44, and each transmission gear is transmitted from the shaft 43 to the shaft 42. Power is transmitted through 46b, 47b, 48b and the like.

  FIG. 1 and FIG. 2 are enlarged views showing the front and rear intermediate portions of the mission case. The front mission case 3 a and the rear mission case 3 b are integrally assembled via a spacer metal 8. The spacer metal 12 is a connecting metal for adjusting the distance between the front and rear axles, penetrating through the inside thereof, a braking oil passage 55, a drive switching oil passage 56 for two-wheel drive and four-wheel drive, and a front wheel speed increasing oil passage 57. Is forming.

  A first metal 5 containing a main pressure reducing valve 4 is attached so as to communicate with each oil passage of the spacer metal 12, and the drive switching of the two-wheel drive / four-wheel drive and the front wheel speed increase switching are performed on the first metal 5. A second metal 8 having a built-in switching valve 7 is attached, and a third metal 10 having a turning brake valve 9 built in is attached to the second metal 8. The change-over valve 7 applies the hydraulic pressure to one of the pair of hydraulic clutches 38 to bring it into a connected state, and drives the front wheels at a standard speed (standard 4WD). (2 speed 4WD) and 2 clutch can be obtained when both clutches are disengaged. The single selector valve 7 can switch 2WD / 4WD and standard 4WD / speed 4WD. It is the structure which can be switched to.

  In addition to the main pressure reducing valve 4, an oil passage leading to the second metal 8 and the third metal 10 is formed in the first metal 5, and an oil passage leading to the third metal 10 is formed in the second metal 8, Even if the oil path of the second metal 8 is closed with a cover plate 11 (not shown) and the third metal 10 is removed, the oil functions without leakage.

  The two-wheel / four-wheel drive switching / front wheel speed increase switching hydraulic clutch 38 is arranged in the front mission case 3a near the spacer metal 12, and the oil path from the front wheel speed increase valve 7 of the third metal 10 is arranged. Is communicated.

FIG. 7 is a hydraulic circuit diagram, and mainly describes the control system hydraulic circuit.
The pressure oil discharged from the hydraulic pump 2 is first sent to the main pressure reducing valve 4 provided on the first metal 5, controlled to a predetermined pressure, and sent to the work machine control oil path 58 and the steering control oil path 59.

  The pressure oil sent to the steering control oil passage 59 is depressurized by the sub pressure reducing valve 60, and sent to the front wheel speed increasing valve 7 provided on the second metal 8 and the turning control valve 9 provided on the third metal 10. The front wheel acceleration switching valve 7 for switching between the 2WD and 4WD operates the hydraulic clutch 38, and the turning control valve 9 operates the brake cylinders 62, 63 of the left and right rear wheels 19, 19.

  The pressure oil sent to the work machine control oil passage 58 is sent to the horizontal control hydraulic device 65 and the main lifting control hydraulic device 66 by the diversion valve 64. The horizontal control cylinder 67 is controlled by a horizontal control hydraulic device 65, and the main lift control cylinder 68 is controlled by a main lift control hydraulic device 66.

  Reference numeral 70 denotes a forward / reverse switching mechanism for switching the rotation of the input shaft 54 in the forward / reverse direction in accordance with the operation of the forward / reverse switching lever 71 near the handle, and 72 is provided on the PTO interlocking shaft 40 to move the shaft 40 in two steps. This is a PTO transmission mechanism that changes speed.

It is a partial enlarged back sectional view. It is a partial enlarged side sectional view. It is a side view of a tractor. It is a power transmission route diagram. It is a partially expanded side sectional view of a mission case. It is a sectional side view of a mission case. It is a hydraulic circuit diagram.

Explanation of symbols

1 Engine 2 Hydraulic pump 3 Mission case 3a Front mission case 3b Rear mission case 3b
4 Main pressure reducing valve 5 First metal 6 Drive switching valve 7 Front wheel speed increasing valve 8 Second metal 9 Swing brake valve 10 Third metal 11 Cover 12 Spacer metal 38 Hydraulic clutch for 2WD / 4WD switching and front wheel acceleration

Claims (3)

  In a track truck that controls operation with hydraulic oil of a hydraulic pump (2) driven by an engine (1), a main pressure reducing valve (4) is built in a side portion of a transmission case (3) that constitutes a vehicle body. Metal (5), second metal (8) with built-in switching valve (7) that controls switching between 2WD and 4WD and front wheel acceleration, and third metal (10) with built-in turning brake valve (9) The oil channel opened to the third metal (10) side of the second metal (8) by removing the third metal (10) located outside and attaching the lid (11) Hydraulic control valve arrangement for mobile agricultural machines, characterized in that it can be closed.   A spacer metal (12) for connecting the front mission case (3a) and the rear mission case (3b) is provided at a position where the first metal (5) of the transmission case (3) is installed, and a swing brake valve is provided on the spacer metal (12). The hydraulic control of the mobile agricultural machine according to claim 1, wherein oil passages (55), (57) of a switching valve (7) that controls drive switching of the two-wheel drive / four-wheel drive and front wheel speed increase switching are formed. Valve arrangement.   The hydraulic control valve arrangement of the mobile agricultural machine according to claim 2, wherein a front wheel speed increasing hydraulic clutch (13) is arranged in the vicinity of the spacer metal (12).

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