JPH0510859U - Work vehicle - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] Although the hydraulic oil in the transmission case is used both to supply hydraulic oil to the hydraulic transmission and to drive hydraulic equipment, the hydraulic transmission and hydraulic equipment By dividing the circulation paths so that they do not intersect with each other, it is possible to prevent air from being mixed into the hydraulic oil in the mission case and to prevent the operation of the hydraulic transmission from being hindered. [Composition] A separate chamber 17 in an open state is provided on the upper part of the transmission case 14 through a narrow communication port 14a, and an oil level OL of the hydraulic oil to be filled is set in the separate chamber 17.
The hydraulic oil supply port 19a of the hydraulic transmission sucks the hydraulic oil in the transmission case, the working machine pump sucks the hydraulic oil in another chamber, and the return oil from the hydraulic device is returned to the other chamber. It was made.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 According to the present invention, a hydraulic transmission that drives a traveling device is installed in a mission case, and a work machine pump that drives a hydraulic device for a work machine attached to a machine body is driven by an input shaft of the hydraulic transmission. In a configured work vehicle, the present invention relates to a technique in which hydraulic oil in a mission case is used both for supplying hydraulic oil for a hydraulic transmission and for driving hydraulic equipment.

[0002]

[Prior Art]

 Conventionally, there is a work vehicle, such as a snow blower, which is attached to a work vehicle and is driven by a hydraulic device such as a hydraulic cylinder so that the work machine pump can be moved up and down and rolled freely. The one configured as a hydraulic unit integrated with a tank is known in Japanese Patent Laid-Open No. 57-104705 and the like, and the one in which a hydraulic transmission that continuously changes the vehicle speed is installed in a mission case is also known. It has become.

[0003]

[Problems to be solved by the device]

 However, if a hydraulic unit such as a hydraulic lifting device is used as a dedicated hydraulic unit for this machine, it becomes expensive and it is necessary to secure an installation space. Therefore, in the case where the hydraulic transmission is installed in the transmission case, the working machine pump is driven by using the input shaft of the hydraulic transmission, and the hydraulic oil in the transmission case is operated by the hydraulic transmission. It may be possible to use it both for refueling and for driving hydraulic equipment.However, when assembling the work equipment pump and hydraulic equipment, or connecting hydraulic equipment and the transmission case with piping, air is present inside the equipment. However, this air mixes in the return oil when the hydraulic equipment is driven and is recirculated into the mission case. The air that has once entered the mission case is agitated by the rotating parts of the hydraulic transmission, etc., causing air bubbles to exist in the hydraulic fluid, causing air trapping when replenishing the hydraulic transmission's hydraulic fluid, and the start feeling is reduced. It was getting worse and making noise from cavitation.

[0004]

[Means for Solving the Problems]

 In order to solve such a problem, the present invention incorporates a hydraulic transmission B for driving a traveling device 10 into a mission case 14 and drives hydraulic equipments 1 and 13 for a working machine A attached to the machine body. In the work vehicle configured to drive the working machine pump C to be driven by the input shaft 11 of the hydraulic transmission B, the mission case 14 has a separate chamber 17 in an open state through a narrow communication port 14a at the upper part thereof. Is provided, the oil level OL of the hydraulic oil to be filled is set in the separate chamber 17, and the working oil supply port 19a of the hydraulic transmission B sucks the hydraulic oil in the transmission case 14 and at the same time, the working machine The pump C sucks the working oil in the separate chamber 17, and the return oil from the hydraulic devices 1 and 13 is returned to the separate chamber 17.

[0005]

【Example】

 The problems to be solved by the present invention and the means for solving the problems are as described above. Next, the structure of the embodiment shown in the accompanying drawings will be described. 1 is a side view of an entire work vehicle equipped with a snow blower as a work machine, FIG. 2 is a plan sectional view of a hydraulic transmission, FIG. 3 is a rear view of a mission case in the first embodiment of the present invention, and FIG. 4 is a rear view of the same. FIG. 5 is a side sectional view, FIG. 5 is a side sectional view, FIG. 6 is a hydraulic circuit diagram, FIG. 7 is a side sectional view in a second embodiment of the present invention, and FIG. 8 is a rear sectional view.

Referring to the overall configuration of the work vehicle in FIG. 1, a snow blower A as a work machine is mounted on the front end of the machine body so as to be able to roll around the output shaft, and attached to the side of the case 3 of the snow blower A. The swinging auger 2 is oscillated by the hydraulic cylinder 1, and a scraping auger 2 is horizontally mounted on the front end of the case 3 and a fan is provided after that to project a chute above the scraping auger 2. The snow is then crushed and scraped, blown upward by a fan, guided by a chute and discharged to the side.

At the rear end of the machine body, a handle 5, an elevating lever 6, and a speed change lever 7 are projected obliquely upward, and crawler type traveling devices 10 are arranged on both lower sides of the body, and the crawler type traveling device 10 and a track frame work together. A hydraulic cylinder 13 for raising and lowering is arranged between the machine frame and the machine frame. The engine E is installed in the front of the fuselage and the mission case 14 is installed in the rear of the fuselage. The output pulley fixed to the output shaft 9 of the engine E is passed through the belt, the counter shaft 12, the pulley, etc. to the mission case 14 The power is transmitted to the input shaft 11 and the speed is changed to drive the drive sprocket fixed to the axle 40 of the crawler type traveling device 10. Power is transmitted from the counter shaft 12 to the fan and the scraping auger 2.

As shown in FIG. 4, in the transmission case 14, a hydraulic transmission B is arranged in the upper part, and an auxiliary transmission and a side clutch are arranged in the lower part. The motor shaft of the hydraulic transmission B is A cooling fan 30 is fixed to the end portion 24 of the transmission case 14 so as to project therefrom. Further, a notched gear 24a is formed on the motor shaft 24 inside the mission case 14 and meshes with the fixed gear 32 on the counter shaft 31, and the fixed gear on the counter shaft 31 is placed on the sub-transmission shaft 33. A sliding gear 36 on the sub-transmission shaft 33 that meshes with the free-fitting gears 34 and 35 and is capable of meshing with the internal gears of the free-fitting gears 34 and 35 is the rotation of the sub-transmission lever 37 disposed outside the transmission case 14. It is dynamically slid to enable high and low speed shifting.

The gear 33a engraved on the auxiliary transmission shaft 33 meshes with the loose fitting gear 39 on the axles 40L and 40R, and the sliding bodies 41L and 41R are provided on both sides of the loose fitting gear 39 via the clutch poles. Is externally fitted to form a side clutch, and the sliding bodies 41L and 41R are slid by rotating a clutch lever 42 provided outside the mission case 14, enabling disconnection and contact of power, and further rotation. When moved, the sliding bodies 41L and 41R can also mesh with the teeth of the mission case 14 to stop the rotation of the axle.

As shown in FIG. 2, the hydraulic transmission B has a structure in which a transmission case 14 and a center section 19 are penetrated by an input shaft 11 which is a pump shaft, and a work machine is provided on a rear outer surface of the transmission case 14. A pump C is attached, and a filter 15 is arranged between the rear inner surface of the mission case 14 and the center section 19. A hydraulic pump P and a hydraulic motor M are formed on the center section 19. The hydraulic pump P has a cylinder 21 fitted on the input shaft 11 and a plurality of pistons 22, 22 ... Disposed around the input shaft 11. And the head of the piston 22 is brought into contact with the variable swash plate 23. In the hydraulic motor M, several cylinders 26, 26, ... Are arranged around the motor shaft 23 in a cylinder 25 fitted onto the motor shaft 23, and the heads of the pistons 26, 26 ,. 27, and a center section 19 between the cylinder 21 and the cylinder 25 is provided with oil passages for discharge and return oil so that they communicate with each other, and the hydraulic pump P and the hydraulic motor M are connected as shown in FIG. A closed circuit is formed between them so that when the hydraulic oil leaks and becomes a negative pressure, it can be supplied from the oil passage 19a opened into the transmission case 14 through the filter 15 through the check valves 29a and 29b. is there. With such a configuration, when the input shaft 11 is driven, the hydraulic pump P operates, and the discharge amount and the discharge direction from the hydraulic pump P change the angle of the variable swash plate 23 connected to the speed change lever 7. The motor shaft 24 of the hydraulic motor M is rotated by this pressure oil to transmit power from the engraved gear 24a to the axle 40 via the auxiliary transmission and the side clutch.

As shown in FIGS. 3 and 5, the working machine pump C is provided with a pump case 16 attached to the mission case 14, and a gear shaft 20 is fixedly provided on the extension of the input shaft 11. A gear pump is configured inside, and a relief valve 18 is also incorporated. The pump case 16 is provided with a suction port S, a drain port D, a tank port T and a hydraulic oil supply port E, which are respectively connected to the hoses 43, 44, 45 and 46, and the other ends of the hoses 43 and 45 will be described later. The hose 46 is connected to the separate chamber 17, the hose 46 is connected to the pump port of the switching valve 50 that switches the expansion and contraction of the hydraulic cylinder 1, and the hose 44 is connected to the drain port of the switching valve 51 that switches the lifting and lowering of the hydraulic cylinder 13. ..

In addition, a communication port 14a is provided at the upper end of the transmission case 14 and has a narrow opening that allows bubbles to easily pass therethrough. A wide-diameter separate chamber is opened through the communication port 14a. 17 are provided. Then, the oil level OL of the working oil to be filled in the mission case 14 is set so as to be positioned up to a midway part in the separate chamber 17, and the working oil is stored in the lower layer part of the separate chamber 17 and the air is stored in the upper layer part. There is. Reference numeral 17b is an oil injection port for hydraulic oil, and a breather cap 52 is fitted into the opening end of the oil injection port to allow only air flow to the outside of the case.

In the separate chamber 17, the hydraulic transmission B is completely immersed in the hydraulic oil of the transmission case, and the oil level OL is set to a high level in order to prevent air entrapment due to rotational stirring, and the operation of the transmission B is performed. Due to this, the hydraulic oil in the mission case 14 has the function of a reserve tank that allows for fluctuations in the oil level OL in anticipation of the expansion and expansion of the hydraulic oil.

The separate chamber 17 may be connected by forming the insertion port 17a at the open end of the communication port 14a by using the tank member having the structure shown in the first embodiment, or the mission case 14a. By utilizing the fact that it is configured as a half mold in the front-back direction of the machine body, as shown in FIG. 7 and FIG. 8 as the second embodiment, when the half mold of the case is molded, the other half of the separate chamber is not used. It is also possible to form the separate chamber 17 by casting and forming by machining and stacking them. Further, a filter 47 is further installed inside the separate chamber 17 and is connected to the hose 43 on the side surface of the separate chamber 17, and the drain hose 45 is connected at a position orthogonal to the connecting portion of the hose 43 and the filter 47. Of.

With the above-described configuration, bubbles generated when the hydraulic oil is filled in the mission case 14 are accumulated in the tank 17 from the upper portion of the mission case 14 via the communication port 14a. When the hydraulic transmission B is operated, the cylinder 21 of the hydraulic pump P and the cylinder 25 of the hydraulic motor M rotate and slide with respect to the center section 19 and the sliding surfaces of the cylinders 21 and 25 and the pistons 22 and 26. The hydraulic oil in the closed circuit that constantly leaks is directly returned to the mission case 14, and the leaked hydraulic oil operates in the mission case 14 from the hydraulic oil supply port 19a of the center section 19 via the filter 15. Oil is sucked in and replenished. In this way, the hydraulic oil around the center section 19 circulates inside and outside the hydraulic transmission B.

On the other hand, the working machine pump C sucks the hydraulic oil in the separate chamber 17 from the suction port S through the hose 43 to turn it into pressure oil, and discharges it from the hydraulic oil supply port E to drive the hydraulic cylinders 1 and 13 through the hose 46. The return oil is selectively driven into the drain port D through the hose 44, merges with the relief discharge oil of the relief valve 18 inside the pump case 16, and returns from the tank port T into the separate chamber 17 through the hose 45. Run away. In this way, the hydraulic oil stored in the separate chamber 17 circulates for driving the hydraulic cylinders 1 and 13. For the oil recirculated into the separate chamber 17 from the hose 45, the recirculation port and the filter 47 are disposed orthogonally to each other, so that the bubbles mixed in the recirculation oil can be easily separated and the suction resistance of the filter 47 is reduced. Further, the filter 47 is arranged at the bottom of the separate chamber 17 in anticipation of the oil level OL decreasing when the hydraulic cylinders 1 and 13 are driven.

As described above, the hydraulic oil in the transmission case 14 is used both for replenishing hydraulic oil for the hydraulic transmission B and for driving the hydraulic cylinders 1 and 13, but the communication port 14a described above is used for both. It acts so as not to intersect the circulation routes of.

The hydraulic transmission B applied to the present invention may have a form having a charge pump for replenishing hydraulic oil, and the hydraulic oil replenishment is performed by self-priming as shown in the embodiment. In the case of the form, it is necessary to give great consideration to the air intrusion into the hydraulic pump or the hydraulic motor, so that the further effect can be achieved.

[0019]

[Effect of the device]

 With the above-described configuration, the bubbles generated when the hydraulic oil is filled in the mission case 14 are collected in the separate chamber 17 from the upper portion of the mission case 14 through the communication port 14a. The hydraulic oil is maintained, and air is not sucked in when replenishing the hydraulic transmission B with hydraulic oil. Also, when assembling piping for hydraulic equipment such as a hydraulic lifting device, air existing in the piping becomes bubbles and is returned together with the hydraulic oil into the separate chamber 17, but these bubbles have narrow communication ports. Moreover, there is no reverse flow into the mission case 14, and the separation from the hydraulic oil can be performed quickly within the tank. Therefore, while the hydraulic oil in the mission case is also used to drive the hydraulic equipment, air is not caught when hydraulic oil is replenished in the hydraulic transmission B, the starting feeling is improved, and noise from cavitation is increased. It was possible to prevent the occurrence of.

[Brief description of drawings]

FIG. 1 is an overall side view of a work vehicle equipped with a snow remover as a work machine.

FIG. 2 is a plan sectional view of a hydraulic transmission.

FIG. 3 is a rear view of the mission case in the first embodiment.

FIG. 4 is a rear sectional view of the same.

FIG. 5 is a side sectional view of the same.

FIG. 6 is a hydraulic circuit diagram.

FIG. 7 is a side sectional view of the second embodiment.

FIG. 8 is a rear sectional view of the same.

[Explanation of symbols]

 A Snow blower B Hydraulic transmission C Working machine pump D Drain port E Hydraulic oil supply port S Suction port T Tank port 1/13 Hydraulic cylinder 14 Mission case 14a Communication port 16 Pump case 17 Tank 19 Center section 19a Oil passage

Claims (1)

[Claims for utility model registration] [Claim 1] The hydraulic transmission B for driving the traveling device 10 is installed in the mission case 14, and the hydraulic devices 1, 13 for the working machine A attached to the machine are driven. In the work vehicle configured to drive the work implement pump C by the input shaft 11 of the hydraulic transmission B, the transmission case 14 is provided with the separate chamber 17 at the upper part thereof via the narrow communication port 14a. The oil level OL of the hydraulic oil to be provided and filled is set in the separate chamber 17, and the working oil supply port 19a of the hydraulic transmission B is set in the mission case 14.
Work in which the working oil in the separate chamber 17 is sucked by the working machine pump C, and the return oil from the hydraulic devices 1 and 13 is circulated into the separate chamber 17 while sucking the working oil in the separate chamber 17. vehicle.