JP3174277B2 - Vehicle hydraulic operating system warming mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a warming mechanism for a hydraulic operating section of a civil engineering or construction vehicle.

[0002]

2. Description of the Related Art In civil engineering and construction vehicles, for example, backhoes, a swivel is mounted on a traveling machine platform having left and right crawler traveling devices, and an engine and an excavator are mounted on the swivel. The crawler traveling device and the swivel table are driven by a hydraulic motor, and the boom, arm and bucket of the excavator are driven by a hydraulic cylinder, and these hydraulic actuators are driven by hydraulic oil from a hydraulic pump driven by an engine. The pressure oil is controlled by a control valve.

A control valve is provided for each actuator and is arranged in a swivel. Some of the control valves are connected to an operation valve in an operation box provided on the swivel through a pilot oil passage. The control valve is operated and controlled by operating the operation valve with an operation lever or the like. The control valve forms a valve block by stacking 8 to 10 valves, and the control valve accommodates (or forms) 8 (or 4 pairs of 2) in a metal block, or controls Like the valve, it is superimposed and placed in the block.

When the vehicle is started, when the temperature of the hydraulic oil is low or when the hydraulic equipment is cold (particularly in winter), the viscosity of the hydraulic oil flowing in the hydraulic operating unit is low, and The warm-up operation must be performed for a sufficient time until the operation response of the actuator becomes dull and the temperature of the hydraulic oil rises to a temperature at which the required viscosity is reached. Therefore, a pressure oil circulation passage (which is closed when the spool moves from the neutral state) is formed in the control valve block so that the pressure oil from the hydraulic pump flows even when the control valve is not operated. Therefore, a structure is adopted in which the control valve block is heated with pressure oil.

[0005]

Conventionally, the control valve block is heated relatively quickly, but the operating valve block is not heated by pressure oil. This is a structure in which the operation valve is directly operated by the operation lever and only supplies pilot pressure oil.It is arranged in a narrow space inside the operation box, and a small and inexpensive valve is used. This is because it is difficult to form a pressurized oil circulation flow path.

However, since the operation valve block is easy to cool and the pilot oil passage is long and narrow, rapid warming of the hydraulic oil at low temperatures is required. According to the present invention, a warm air flow path is formed in a valve block that houses an operation valve, and an oil discharge path of a control valve is connected to an oil tank bypassing the warm air flow path, so that the operation valve of the operation valve is started at the time of vehicle operation start. It is an object of the present invention to provide a warming mechanism for a hydraulic operating section of a vehicle that can rapidly warm up a valve block.

[0007]

A first concrete means for solving the problems in the present invention is a hydraulic pump 3 driven by an engine 2 and a supply of hydraulic oil from the hydraulic pump 3 to a plurality of actuators. A plurality of control valves 4 and operating valves 5 respectively operating the plurality of control valves 4 with pressure oil from the hydraulic pump 3, and a valve block 6 containing the operating valves 5.
A warm air flow path 7 is formed therein, and the oil discharge path 8 of the control valve 4 is connected to an oil tank 9 bypassing the warm air flow path 7.

Accordingly, the warm oil discharged through the control valve 4 is circulated through the warm air passage 7 into the valve block 6,
The drain oil warms the operation valve 5 and the pilot oil passage between the operation valve 5 and the control valve 4. The second specific means for solving the problem in the present invention is, in addition to the first specific means,
A plurality of oil passages 8 connected to the plurality of control valves 4 are formed, and all or a part of the plurality of oil passages 8 are connected to the warm air passage 7.

As a result, all or a part of the warm oil discharged through the control valve 4 is transferred to the valve block 6 through the warm air passage 7.
The operation valve 5 and the pilot oil passage between the operation valve 5 and the control valve 4 are warmed up by a required amount of drainage oil. A third concrete means for solving the problem in the present invention is a circulating flow for circulating and circulating the pressure oil from the hydraulic pump 3 when the control valve 4 is neutral, in addition to the first or second concrete means. Road 10
Is formed in the control valve 4, and the circulation passage 10 is connected to the oil discharge passage 8 on the upstream side of the warm air passage 7.

As a result, the control valve 4 is rapidly warmed up by the pressurized oil flowing into the circulation passage 10, and the oil discharged through the circulation passage 10 is further discharged through the warm-up passage 7 to the valve block 6. And the control valve 5 is heated.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 3, reference numeral 15 denotes a so-called small ultra-small turning type backhoe exemplified as a vehicle. The backhoe 15 has a pair of crawler traveling devices 17 on the left and right sides of a traveling machine base 16. A substantially circular swivel 18 is rotatably mounted on the vertical axis, and an excavator 19 is mounted on the front right side of the swivel 18, and a control box 20 is disposed on the upper left front. A driver's seat 21 is arranged in the vehicle, a sunshade device 22 for covering the driver's seat 21 is provided on the swivel 18, and the dozer 23 is arranged to protrude forward from the traveling machine base 16.

The diameter of the turntable 18 is set to be equal to or less than the distance between the outer ends of the left and right crawler traveling devices 17, and the excavator 19 is folded and stored so as not to protrude from the turntable 18. The crawler traveling device 17 is driven by a hydraulic motor 26, the swivel 18 is driven by a hydraulic motor (not shown), and the dozer 23 is movable up and down by a hydraulic cylinder 27.

The excavator 19 is supported by the swivel table 18 so as to be vertically swingable, and is swingable by a boom cylinder 28. The excavator 19 is connected to the tip of the boom 29 via an intermediate support shaft. An intermediate boom 31 oscillated by the offset cylinder 30, a tip boom 33 connected to the tip of the intermediate boom 31 via a tip support shaft, and connected to the base boom 29 via a link link 32;
An arm 35 connected to the distal end boom 33 via a horizontal axis and oscillated by an arm cylinder 34, and a bucket 37 connected to the distal end of the arm 35 via a horizontal axis and dumped by a bucket cylinder 36 are provided. Have.

The engine 2 is mounted on the rear portion of the swivel 18. The engine 2 has an oil pan 11 and a radiator fan for cooling the radiator 12 on one side.
A hydraulic pump 3 driven by a crankshaft is provided on the other side of the engine 2, a driver's seat 21 is disposed on a bonnet 40 that covers the hydraulic pump 3, and a fuel tank and an oil tank 9 are mounted on the right side of the swivel 18. Have been.

1 to 3, the hydraulic pump 3 includes:
For example, it has four hydraulic pumps 3A, 3B, 3C, and 3D, and the hydraulic pumps 3A, 3B, and 3C are triple pumps.
(Shown by solid lines in FIGS. 1 and 2) to the control valve 4 and the operation valve 5 which constitute a hydraulic operation unit in front of the swivel 18.
Oil discharged from each control valve 4 and the relief valve, etc.
(Shown by a dashed line in FIGS. 1 and 2)
Is returned to. The oil drained from the operation valve 5 is returned to the oil tank 9 via an oil drain as appropriate.

The control valve 4 is disposed at a front portion in the swivel table 18.
1, the arrangement of the control valves 4A for the arm cylinder 34, the control valve 4B for the left traveling motor 26, the control valve 4C for the service port, the control valve 4D for the right traveling motor 26, and the Control valve 4E, control valve 4F for boom cylinder 28, control valve 4G for swing motor, control valve 4H for offset cylinder 30, dozer cylinder 27
Control valve 4J. The arrangement of the control valve 4 can be changed as appropriate, and a control valve for switching the traveling motor 26 from a low speed to a high speed may be added.

The hydraulic oil from the hydraulic pumps 3A, 3B, 3C is sent to the actuator supply ports of all the control valves 4A to 4J via the hydraulic oil passage 39, and can operate four actuators at the same time. Even when the motor 26 is in the straight running state, the actuators such as the turning motor, the offset cylinder 30 and the dozer cylinder 27 can be operated.

A circulation flow path 10 is formed through all (or a part of) the control valves 4A to 4J.
Pressure oil is supplied from the hydraulic pumps 3. The control valve 4 is warmed up at the start of operation by the pressure oil flowing through the circulation flow path 10. The circulation flow path 10 is closed when the spool is moved by operating the control valve 4 from the neutral state.

The operation valves 5 are arranged in the control box 20. For example, eight operation valves are arranged in the valve block 6, and are switched by swinging the two operation levers 43R and 43L back and forth and right and left. Operated, four control valves 4
A, 4E, 4F, and 4G can be controlled and operated via pilot oil passages (shown by chain lines in FIGS. 1 and 2). The other five control valves 4B, 4C, 4D, 4H, 4J, etc. are manually operated by operating levers or foot pedals.

The arrangement of the operation valves 5 is sequentially operated from the right by swinging the right operation lever 43R back and forth and the control valve 4F
Boom vertical movement operation valve 5A, bucket dump / plowing operation valve 5B, left operation lever 4 which is operated by right and left swing of right operation lever 43R and connected to control valve 4E.
Arm dumping / peking operation valve 5C, which is operated by 3L back-and-forth swing and connected to control valve 4A, left operation lever 43L
, And a turntable left / right rotation operation valve 5D connected to the control valve 4G. The forward and backward swings and the left and right swings of the left and right operation levers 43R and 43L may be set in reverse.

The pressure oil from the hydraulic pump 3D is supplied to the working oil passage 3
9 and all the operation valves 5A to 4D via the electromagnetic switching valve 44
When the required operation valve 5 is opened by the left and right operation levers 43R and 43L, the pressure in the pilot oil passage 47 of the opened operation valve 5 rises and is connected to the pilot oil supply port. The control valve 4 is switched and controlled.

The valve block 6 is made of an aluminum casting, a cast iron casting, or a metal such as other metals or alloys, and has an operating valve 5 formed or inserted therein. One or a plurality of warm air passages 7 are formed so as to surround. This warm air passage 7
Are connected to an oil drain 8 so that the oil discharged from the control valve 4 once passes through the warm air passage 7 and reaches the oil tank 9. The operation valve 5 can be warmed up by diverting the oil, particularly the waste oil that has passed through the circulation passage 10, to the warm-up passage 7.

The oil drain 8 is formed by joining an oil drain 8a through which oil from the control valves 4A to 4F flows, and an oil drain 8b through which oil from the control valves 4G to 4J flows. The oil passage 9 is connected to an oil tank 9 via an oil filter (not shown). The warm air flow path 7 is connected to an oil drain 8a or 8b to be connected to an oil drain 8b. The section may be used for warm air.

Reference numeral 45 denotes a check valve provided near the oil filter of the oil drain passage 8 for preventing cavitation when sucking oil from the oil tank 9. Reference numeral 46 denotes a hydraulic pump when the operation lever 43 is not operated. It is a relief valve for releasing pressure oil from 3D, and is joined to another oil discharge passage 8 via an oil discharge passage 8c and connected to an oil tank 9.

If the oil discharge passage 8c on the relief valve 46 side is connected to the oil discharge passage 8 upstream of the warm air flow path 7, the oil discharged from the relief valve 46 also flows into the warm air flow path 7. The relief valve 46 always drains oil when the operation lever 43 is not operated, and the drainage oil temperature rises relatively quickly at the start of operation, which is effective for warming up the valve block 6.

The oil discharged from the relief valve 46 is supplied to the oil discharge passage 8c.
By connecting the warm air passage 7 to the other oil drain passages 8a,
8b, the valve block 6 can be warmed independently. However, since the amount of oil is small, the warming of the valve block 6 is more effectively performed by draining oil from the hydraulic pumps 3A to 3J. It is more effective to combine the drain oils and flow them into the warm air flow path 7.

The present invention is not limited to the above embodiment, but can be variously modified. For example,
The number of the hydraulic pumps 3 may be plural or one other than four, and the control valve 4 and the operating valve 5 may be plural.

[0028]

According to the present invention described in detail above, the operation valve 5
A warm air flow path 7 is formed in a valve block 6 in which the oil is stored.
, The oil discharged through the control valve 4 flows through the warm air flow path 7 into the valve block 6, and is controlled by the operating valve 5 and the pilot oil passage 47 between the operating valve 5 and the control valve 4. Etc. can be heated.

Further, since a plurality of oil passages 8 connected to the plurality of control valves 4 are formed, and all or a part of the plurality of oil passages 8 are connected to the warm air passage 7, the control valve 4 All or a part of the drained oil that has passed through the valve block 6 is passed through the warm air flow path 7, and the pilot oil between the operating valve 5 and the operating valve 5 and the control valve 4 is discharged with a required amount of drained oil. The road 47 can be warmed. Further, when the control valve 4 is in a neutral position, a circulation passage 10 for circulating the pressure oil from the hydraulic pump 3 is formed in the plurality of control valves 4, and the circulation passage 10 is discharged upstream of the warm air passage 7. Oil passage 8
, The control valve 4 is quickly warmed up by the pressure oil flowing in the circulation flow path 10, and then is circulated through the warming flow path 7 into the valve block 6 to warm up the operation valve 5. Can be.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a schematic explanatory view showing the main part.

FIG. 3 is a perspective view of a backhoe.

[Explanation of symbols]

 2 Engine 3 Hydraulic pump 4 Control valve 5 Operating valve 6 Valve block 7 Warm air passage 8 Drainage passage 9 Oil tank 10 Circulation passage

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E02F 9/00 E02F 9/22

Claims (3)

(57) [Claims] A hydraulic pump (3) driven by an engine (2), a plurality of control valves (4) for supplying hydraulic oil from the hydraulic pump (3) to a plurality of actuators, and a hydraulic pump (3). And a control valve (5) for operating each of the plurality of control valves (4) with the pressure oil from (1), and a warm air flow path (7) in a valve block (6) containing the control valve (5). Forming
A hydraulic operating unit warming mechanism for a vehicle, wherein an oil drain (8) of the control valve (4) is connected to an oil tank (9) bypassing a warm air flow path (7). 2. A plurality of oil passages (8) connected to the plurality of control valves (4), and all or a part of the plurality of oil passages (8) are connected to a warm air passage (7). The warming-up mechanism according to claim 1, wherein the mechanism is connected. 3. A circulation channel (1) for circulating and flowing pressure oil from a hydraulic pump (3) when the control valve (4) is neutral.
The control valve (4) is formed with the circulation passage (10), and the circulation passage (10) is connected to the oil drain passage (8) upstream of the warm air passage (7). 3. The warm-up mechanism for a hydraulic operating unit of the vehicle according to 2.