JP2000220768A - Temperature rising circuit for solenoid valve unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature rising circuit for a solenoid valve unit capable of improving operability in low temperature and warming up function even with only a small addition of the number of components by improving warming up performance of a solenoid valve such as a proportional solenoid valve. SOLUTION: A flow of a hydraulic oil for warming up is diverged into two and a check valve 44 is provided in an oil passage of one of the flows. Each valve pressure port 21 of a solenoid valve 3 is connected to one common pressure oil passage 42 and each valve tank port 22 of the solenoid valve 3 is connected to one common tank oil passage 43. The hydraulic oil from an oil pressure inlet 39 passes through an inlet side oil passage 40 from the oil pressure inlet 39 and is diverged into two, and one of them flows into the common oil pressure oil passage 42 via the check valve 44 and the other flows into the common tank oil passage 43.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating circuit for a solenoid valve unit, and more particularly to a heating circuit for a solenoid valve unit such as a proportional solenoid valve unit mounted on a working machine such as a hydraulic power shovel. is there.

[0002]

2. Description of the Related Art When a conventional proportional solenoid valve is used in an actual vehicle such as a hydraulic power shovel, there has been a problem that the operating feeling particularly at low temperatures is deteriorated. That is, the viscosity of the hydraulic oil increases due to the low temperature, and the response to the operation lever and the hysteresis are affected, so that the operation feeling deteriorates. Further, unlike a large control valve (main valve) and the like, the proportional solenoid valve has a problem that it is difficult to warm up (heat) in a normal use state because the amount of flowing hydraulic oil is small. Therefore, in the standby state of the actual machine, a method of warming up by positively flowing oil from the hydraulic oil tank side to the proportional solenoid valve is adopted. For example, there is JP-A-7-26589.

FIG. 6 is a schematic circuit diagram showing a conventional warm-up configuration (heating circuit). The solenoid valve unit 1 is equipped with a heating circuit 2. The solenoid valve unit 1 has a plurality of (for example, four) proportional solenoid valves 3 (electromagnetic valves), a hydraulic inlet 4 (P port), and a tank heat inlet 5.
(TH port), a tank outlet 6 (T port), and an actuator outlet 7 (A port). A pressure source 9 (pilot pump) and a hydraulic oil tank 10 are connected to the hydraulic inlet 4 via a manual remote control valve 8 (hydraulic operation valve), and an actuator outlet 7 is connected via a control valve 11 (directional switching valve). It is connected to an actuator 12 (an operating cylinder such as a hydraulic power shovel). The illustrated circuit is a circuit for limiting the working area of the hydraulic power shovel (for example, limiting the depth of the hole), and independently controls the pressure oil passage 13 from the hydraulic inlet 4 to the proportional solenoid valve 3. It is adopted when used.

The solenoid valve unit 1 has a tank heat inlet 5
A common tank line 15 to the tank outlet 6 via the tank side branch point 14. This common tank line 15
A check valve 17 is provided between the oil pressure inlet 4 and the pump-side branch point 16 from each hydraulic pressure inlet 4. Each proportional solenoid valve 3 is connected to the tank outlet 6 at a tank side connection point 18. The first orifice 1 is located at the most upstream side of the common tank line 15.
9 and a second orifice 20 at the most downstream side.

[0005] The heating circuit 2 allows the hydraulic oil from the pressure source 9 to flow to the tank outlet 6 and the hydraulic inlet 4 via the tank heat inlet 5 and the common tank line 15, and to cause the proportional solenoid valve 3 or its solenoid valve unit 1 to operate. The temperature can be raised.

In the solenoid valve unit 1 and the temperature raising circuit 2 having such a configuration, the proportional solenoid valve 3 is disposed between the manual remote control valve 8 and the control valve 11 to restrict the operation of the manual remote control valve 8. It is assumed that. The warm-up state is set at the stop position of the manual remote control valve 8 (lock valve). That is, in this warmed-up state, the hydraulic oil is supplied from the pressure source 9 to the tank heat inlet 5, and the hydraulic oil at the flow rate regulated by the first orifice 19 is supplied from the common tank line 15 to the check valve 17, each hydraulic inlet 4 and the hydraulic oil tank 10 through the manual remote control valve 8 and the like. On the other hand, the hydraulic oil that could not be removed at each hydraulic pressure inlet 4 is:
It passes through the common tank line 15, the second orifice 20, and the tank outlet 6 to the hydraulic oil tank 10.

However, in the temperature raising circuit 2 of the solenoid valve unit 1 having such a configuration, an oil passage (pressure oil passage 13) between the pump side branch point 16 and the valve pressure port 21 of the proportional solenoid valve 3, and furthermore, There is a problem that the oil passage between the tank side branch point 14 and the valve tank port 22 does not warm. Further, there is a problem that there is no flow of the operating oil for warming directly including the valve portion of the proportional solenoid valve 3 including the valve actuator port 23.

[0008] As the need for electronic power shovels has increased, solenoid valve units have been developed that are compatible with systems using electronic remote controls, in contrast to conventional hydraulic remote controls. However, the problem of operating feeling at low temperatures has not been solved even in a heating circuit (not shown) for use.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to provide a heating circuit of a solenoid valve unit in which the warm-up performance of a solenoid valve such as a proportional solenoid valve is improved. As an issue.

Another object of the present invention is to provide a heating circuit of a solenoid valve unit which can improve operability at low temperatures.

Another object of the present invention is to provide a temperature increasing circuit of a solenoid valve unit which can improve a warming-up function even with addition of a small number of parts.

[0012]

That is, the present invention focuses on branching the flow of the operating oil for warming up into two and providing a check valve in the oil passage of one of the flows.
Forming a hydraulic inlet and a tank outlet, a heating circuit of a solenoid valve unit having a plurality of solenoid valves each having a valve pressure port and a valve tank port, wherein the valve pressure port of each of the solenoid valves is
While connecting these to one common pressure oil passage, the valve tank ports of each of the solenoid valves connect these to one common tank oil passage, and hydraulic oil from the hydraulic pressure inlet flows from the hydraulic pressure inlet to the hydraulic pressure inlet. The solenoid valve unit is characterized in that it branches into two through an inlet-side oil passage, one of which flows through the check valve to the common pressure oil passage, and the other flows into the common tank oil passage. This is a heating circuit.

The solenoid valve unit has a two-position three-port valve and forms a second hydraulic pressure inlet. In this two-position three-port valve, the most downstream side of the common pressure oil passage is connected to the second hydraulic port. The second hydraulic pressure inlet and the tank outlet can be switched.

The solenoid valve unit has a two-position four-port valve connected to the inlet-side oil passage. In the two-position four-port valve, the most downstream side of the common-pressure oil passage and the inlet side before branching. The oil passage may be switched between the hydraulic inlet and the tank outlet.

In the temperature raising circuit of the solenoid valve unit according to the present invention, the flow of the warming-up operating oil is branched into two, a common pressure oil passage and a common tank oil passage, and a check valve is provided in one of the common pressure oil passages. Is provided, the portion of the oil passage inside the solenoid valve unit that cannot be warmed up is extremely reduced, and an effective heating circuit can be constructed by adding a few parts. This has the effect of improving the warm-up performance at the time, improving the operation feeling, and suppressing the cost and size.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a temperature raising circuit of a solenoid valve unit according to a first embodiment of the present invention will be described with reference to FIGS. However, the same parts as those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 1 is a schematic circuit diagram of an operation circuit 30 such as a hydraulic power shovel. The operation circuit 30 includes an electromagnetic valve unit 31 corresponding to the electromagnetic valve unit 1, the hydraulic oil tank 10, and the pressure source 9 ( Pilot pump) and relief valve 3
2, a lock valve 33, the control valve 11 and the actuator 12, a main pump 34,
Operation lever 35 (joystick) and control means 36
And the temperature raising circuit 37 (refer to FIG. 2 for details). The operation of the operation lever 35 causes the solenoid valve unit 31 to operate.
A plurality of proportional solenoid valves 3 are driven to generate a pilot oil pressure, and the pilot oil pressure moves the control valve 11 to operate the actuator 12. By switching the lock valve 33 to the illustrated state, the electromagnetic valve unit 31 itself is in a standby state,
A warm-up state in which the solenoid valve unit 31 is warmed up.

FIG. 2 is a circuit diagram showing the configuration of the proportional solenoid valve 3 and the temperature raising circuit 37 in the solenoid valve unit 31. The solenoid valve unit 31 has the tank outlet 6 (T port) and the hydraulic inlet 4 , A second hydraulic inlet 38 (P port), a pump heat inlet 39 (hydraulic inlet, PH port), and the actuator outlet 7 (A port). The heating circuit 37 is connected to the pump heat inlet 39 of the solenoid valve unit 31 and the inlet side oil passage 40.
At the inlet side branch point 41 to a common pressure oil passage 42 and a supply tank oil passage 43.

A check valve 44 and a first orifice 45 are provided in the common pressure oil passage 42, and an electromagnetic switching valve 46 is connected to the most downstream side thereof. The common pressure oil passage 42 is connected to the valve pressure port 21 of each proportional solenoid valve 3 via a valve side branch point 47, and is electromagnetically switched via a downstream branch point 48 (the most downstream side of the common pressure oil passage 42). Connect to inlet port 49 of valve 46.

The electromagnetic switching valve 46 is a two-position three-port valve, the pressure port 50 of which is connected to the second hydraulic inlet 38, and the tank port 51 which is connected from the supply tank oil passage 43 to the tank outlet 6. The valve tank port 22 of the proportional solenoid valve 3 is connected to a common tank oil passage 43, and the valve actuator port 23 is connected to the control valve 11 from the actuator outlet 7.

The common tank oil passage 43 has a second orifice 52 formed therein.

3 and 4 are external views of the solenoid valve unit 31. FIG. 3 is a sectional view taken along line III-III of FIG. 4, and FIG. 4 is a sectional view taken along line IV-IV of FIG. . As shown in FIGS. 3 and 4, each valve pressure port 21 of each proportional solenoid valve 3 is commonly connected to a common pressure oil passage 42, and each valve tank port 22 is connected to a common tank oil passage. 43 are commonly connected. Therefore, the passage of the hydraulic oil in the common pressure oil passage 42 and the common tank oil passage 43 warms up the valve housing 53 of the proportional solenoid valve 3 and the spool 54 therein.

In the electromagnetic valve unit 31 and the temperature raising circuit 37 having such a configuration, as shown in FIG. 2, hydraulic oil is supplied to the pump heat inlet 39 and the inlet side oil passage 40 at the stop position of the lock valve 33 (FIG. 1). The common pressure oil passage 42 and the common tank oil passage 4
Branch to 3. Check valve 4 which flows to common pressure oil passage 42
The flow rate of the hydraulic oil having passed through the electromagnetic switching valve 4 is regulated by the first orifice 45 and the downstream side branch point 48.
Go through 6. Here, when the electromagnetic switching valve 46 is "ON", the pressure port 50 thereof and the second hydraulic pressure inlet 38,
Further, the oil flows into the hydraulic oil tank 10 via the lock valve 33. When the electromagnetic switching valve 46 is “OFF” (the state shown in FIG. 2), the solenoid valve 46 escapes from the tank outlet 6 to the hydraulic oil tank 10. If the inlet port 49 is opened from the pressure port 50 when the electromagnetic switching valve 46 is turned “ON” or in a normal state, the piping of the second hydraulic inlet 38 can be warmed up. Hydraulic oil branched from the inlet-side branch point 41 and flowing into the common tank oil passage 43 has its flow rate regulated by the second orifice 52, passes through the common tank oil passage 43, and flows from the tank outlet 6 to the hydraulic oil tank 10. Exit.

As shown in FIGS. 3 and 4, in the solenoid valve unit 31, the common pressure oil passage 42 and the common tank oil passage 43 pass directly around the outer circumference of each proportional solenoid valve 3. Except for a part of the valve actuator port 23 of the valve 3, most of the hydraulic oil inside the electromagnetic valve unit 31 and the part in contact with the hydraulic oil can be warmed.

Thus, as for the number of parts, the cost and the size can be reduced only by adding the check valve 44 and the electromagnetic switching valve 46. In the warmed-up state, the actuator port 23 of each proportional solenoid valve 3
Since no pressure is generated, no pressure rise occurs at the actuator outlet 7, and there is no fear that the control valve 11 may be operated carelessly.

In the present invention, the electromagnetic switching valve 46 shown in FIG.
And the positions of the first orifice 45 and the second orifice 52 are arbitrary. For example, a configuration as shown in FIG. 5 can be adopted. That is, FIG. 5 is a circuit diagram showing a configuration of the temperature raising circuit 61 of the solenoid valve unit 60 according to the second embodiment of the present invention.
Has an electromagnetic switching valve 62 as a 2-position 4-port valve.

An electromagnetic switching valve 62 is provided in an inlet side oil passage 63 between the second hydraulic pressure inlet 38 and the inlet side branch point 41. The pressure port 64 and the tank port 65 of the electromagnetic switching valve 62 are connected to the second hydraulic inlet 38 and the tank outlet 6, respectively, and the inlet port 66 is connected to the inlet-side branch point 41 via the inlet-side oil passage 63. The first orifice 45 is formed on the way.

Further, the outlet port 67 of the electromagnetic switching valve 62 is connected to the downstream branch point 48 of the common pressure oil passage 42, and the check valve 44 is provided in the common pressure oil passage 42 near the inlet branch point 41. In addition, the second orifice 52 is provided in the common tank oil passage 43.

In the electromagnetic valve unit 60 and the temperature raising circuit 61 having such a configuration, the electromagnetic switching valve 62 is connected to the “OF
F "is a warm-up state, the hydraulic oil from the second hydraulic pressure inlet 38 passes through the inlet port 66, and its flow rate is regulated by the first orifice 45. Branching at a branch point 41, the common pressure oil passage 42
2 through the common tank oil passage 43 and the heating circuit 37 of FIG.
As in the case of (1), the solenoid valve unit 60 or the respective proportional solenoid valves 3 are warmed. During normal operation when the electromagnetic switching valve 62 is “ON”, the proportional electromagnetic valve 3 can be operated by the pressure of the hydraulic oil from the second hydraulic pressure inlet 38.

[0029]

As described above, according to the present invention, a common pressure oil passage and a common tank oil passage are provided for warming up a solenoid valve portion such as a proportional solenoid valve in a solenoid valve unit. In addition, the warm-up state of the solenoid valve can be efficiently realized at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic circuit diagram of an operation circuit 30 such as a hydraulic power shovel provided with a temperature increasing circuit 37 of an electromagnetic valve unit 31 according to a first embodiment of the present invention.

FIG. 2 shows a proportional solenoid valve 3 in the solenoid valve unit 31;
FIG. 3 is a circuit diagram showing a configuration of a heating circuit 37.

FIG. 3 is a sectional view taken along line III-III of FIG. 4;

FIG. 4 is a sectional view taken along the line IV-IV of FIG. 3;

FIG. 5 is a circuit diagram showing a configuration of a temperature raising circuit 61 of an electromagnetic valve unit 60 according to a second embodiment of the present invention.

FIG. 6 is a schematic circuit diagram showing a conventional warm-up configuration (heating circuit 2 of solenoid valve unit 1).

[Explanation of symbols]

1 Solenoid valve unit (Fig. 6) 2 Heating circuit of solenoid valve unit 1 3 Proportional solenoid valve (solenoid valve) 4 Hydraulic inlet (P port) 5 Tank heat inlet (TH port) 6 Tank outlet (T port) 7 Actuator outlet (A port) 8 Manual remote control valve (hydraulic operation valve) 9 Pressure source (pilot pump) 10 Hydraulic oil tank 11 Control valve (direction switching valve) 12 Actuator (Cylinder for operation such as hydraulic power shovel) 13 Pressure oil path 14 Tank Side branch point 15 Common tank line 16 Pump side branch point 17 Check valve 18 Tank side connection point 19 First orifice 20 Second orifice 21 Valve pressure port of proportional solenoid valve 3 22 Valve tank port of proportional solenoid valve 3 23 Proportional Valve actuator port 30 of solenoid valve 3 Power shovel, etc. Working Circuit (FIG. 1) 31 Solenoid Valve Unit 32 Relief Valve 33 Lock Valve 34 Main Pump 35 Operating Lever (Joystick) 36 Control Means 37 Heating Circuit of Solenoid Valve Unit 31 (First Embodiment, FIG. 2) 38 2 hydraulic pressure inlet (P port) 39 pump heat inlet (hydraulic pressure inlet, PH port) 40 inlet side oil passage 41 inlet side branch point 42 common pressure oil passage 43 common tank oil passage 44 check valve 45 first orifice 46 electromagnetic switching Valve 47 Valve-side branch point 48 Downstream-side branch point (most downstream side of the common pressure oil passage 42) 49 Inlet port of the electromagnetic switching valve 46 50 Pressure port of the electromagnetic switching valve 46 51 Tank port of the electromagnetic switching valve 46 52 Second Orifice 53 Valve housing of proportional solenoid valve 3 54 Spool of proportional solenoid valve 3 60 Solenoid valve unit (FIG. 5) 61 Temperature increasing circuit of magnetic valve unit 60 (second embodiment, FIG. 5) 62 electromagnetic switching valve 63 inlet side oil passage 64 pressure port of electromagnetic switching valve 62 65 tank port of electromagnetic switching valve 62 66 of electromagnetic switching valve 62 Inlet port 67 Outlet port of electromagnetic switching valve 62

Continued on front page F-term (reference) 2D003 AA01 AB07 BA01 BA02 BB13 DA03 DA04 3H066 AA07 BA36 BA38 3H089 AA85 BB21 CC01 DA02 DB46 DB49 EE04 EE07 EE13 EE15 EE17 EE22 JJ02

Claims (3)

[Claims] 1. A temperature raising circuit for an electromagnetic valve unit having a plurality of solenoid valves each having a hydraulic pressure inlet and a tank outlet and having a valve pressure port and a valve tank port, respectively, wherein each of the solenoid valves has a valve. The pressure ports connect them to one common pressure oil passage, and the valve tank ports of each of the solenoid valves connect them to one common tank oil passage, and the hydraulic oil from the hydraulic inlet is It branches into two through an inlet side oil passage from the hydraulic pressure inlet, one of which flows to the common pressure oil passage via a check valve, and the other flows to the common tank oil passage. Heating circuit for solenoid valve unit. 2. The solenoid valve unit has a two-position three-port valve and forms a second hydraulic pressure inlet. In the two-position three-port valve, the most downstream side of the common pressure oil passage is 2. The temperature raising circuit for an electromagnetic valve unit according to claim 1, wherein the switching is made between the second hydraulic pressure inlet and the tank outlet. 3. The electromagnetic valve unit has a two-position four-port valve connected to the inlet-side oil passage, and in the two-position four-port valve, the two-position four-port valve is the most downstream side of the common pressure oil passage and before the branch. 2. The temperature raising circuit for an electromagnetic valve unit according to claim 1, wherein an inlet-side oil passage is switched between the hydraulic pressure inlet and the tank outlet.