JP2002327713A - Oil cooling apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To downsize an oil cooling apparatus and to fully recover heat generated in an actuator. SOLUTION: A low-temperature tub 34 storing cooled oil, a high-temperature tub 35 storing high-temperature returned oil, a first oil pump 43 sucking oil in the low-temperature tub 34 connected with the high-temperature tub 35 and an actuator 44 which is operated by receiving oil discharged from the first oil pump are provided. A first passage draining oil of the actuator 44 to the high-temperature tub 35, a second oil pump 45 sucking oil in the high- temperature tab 35 connected with the low-temperature tab 34, and an oil cooler 15 which cools oil discharged from the second oil pump 45 are also provided. Further, a second passage draining oil from the oil cooler 15 to the low- temperature tub 34 is provided. Consequently, a difference between temperature of oil in an inlet side and that of refrigerant in the inlet side in the oil cooler 15 can be enlarged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an oil cooling device.

[0002]

2. Description of the Related Art Conventionally, an injection molding machine is provided with an injection device, a mold device, and a mold clamping device. By driving, the screw can be rotated or moved forward and backward. Further, the mold apparatus includes a fixed mold and a movable mold. By operating the mold clamping device, the movable mold is brought into contact with and separated from the fixed mold, and the mold is closed, clamped and opened. be able to.

[0003] In the measuring step, when the screw is rotated, the resin supplied from the hopper into the heating cylinder is heated, melted, advanced, and stored in front of the screw head. Further, in the injection step, when the screw is advanced, the resin stored in front of the screw head is injected from the injection nozzle,
The cavity is filled in the mold device.

A hydraulic circuit is provided in a hydraulic injection molding machine. The hydraulic circuit includes an oil pump for generating oil pressure, a hydraulic motor for rotating a screw in an injection device, and a reciprocating screw. An actuator such as an injection cylinder for operating the toggle mechanism in the mold clamping device,
By driving the oil pump, the oil sucked from the oil tank is supplied to each of the actuators via an oil passage and various valves.

When each of the actuators is operated, the hydraulic pressure is converted into a mechanical force in the actuator. The oil is discharged when the oil discharged from the oil pump passes through an oil passage. The temperature of the oil increases due to line resistance and the heat generated by the conversion of the hydraulic pressure to mechanical force. Therefore, an oil cooling device is provided in the hydraulic circuit, and the oil is cooled by the cooling device and maintained at an appropriate temperature.

FIG. 2 is a conceptual diagram of a conventional oil cooling device.

In the figure, 12 is an oil tank, 13 is an oil pump for generating hydraulic pressure, 14 and 16 are first and second actuators, and 15 is an oil cooler.

In this case, when the oil pump 13 is driven, the oil in the oil tank 12 is sucked by the oil pump 13 via the oil passage L-1 and after passing through the oil passage L-2, the branch point p1 And a part of the oil is sent to the first actuator 14 via an oil passage L-3, and after actuating the first actuator 14, an oil cooler is provided via an oil passage L-4. After being sent to the oil cooler 15 and cooled in the oil cooler 15, the oil is drained to the oil tank 12 via the oil passage L-5. The remaining oil is sent to the second actuator 16 via the oil passage L-6, and after the second actuator 16 is operated, the remaining oil is drained to the oil tank 12 via the oil passage L-7. You.

A part of the oil is sent to the oil cooler 15 and cooled by the oil cooler 15 and then drained to the oil tank 12, and the remaining oil is drained to the oil tank 12 without being cooled. However, it is also possible to send all the oil to the oil cooler 15, cool the oil, and then drain the oil to the oil tank 12.

FIG. 3 is a conceptual diagram of another conventional oil cooling device.

In FIG. 1, reference numeral 12 denotes an oil tank; 23, a first oil pump for generating oil pressure for operating an actuator 24; 25, a second oil pump for generating oil pressure for sending oil to an oil cooler 15. It is.

In this case, when the first oil pump 23 is driven, the oil in the oil tank 12 is sucked by the first oil pump 23 via the oil passage L-11 and passes through the oil passage L-12. Then, it is sent to the actuator 24, and after operating the actuator 24, it is drained to the oil tank 12 via the oil passage L-13. Then, when the second oil pump 25 is driven, the oil in the oil tank 12 is discharged to the oil passage L-1.
4, the oil is sucked by the second oil pump 25, sent to the oil cooler 15 through the oil passage L-15, cooled in the oil cooler 15, and then cooled in the oil tank 12 through the oil passage L-16. Drained. In this case, the oil in the oil tank 12 is sent to the oil cooler 15 separately from the operation of the actuator 24, and is cooled in the oil cooler 15.

[0013]

However, in the conventional oil cooling device, since the amount of heat generated in each actuator increases as the size of the injection molding machine increases, it is necessary to sufficiently cool the oil. In addition, it is necessary not only to increase the capacity of the oil cooler 15 but also to increase the discharge amount of the oil pump in order to supply a sufficient amount of oil to the oil cooler 15. Oil cooler 1
In order to supply a sufficient amount of cooling medium, for example, cooling water, to the oil cooler 15, the discharge amount of a cooling medium pump (not shown) needs to be increased. As a result, the size of the oil cooling device increases accordingly.

When the oil cooled and high-temperature oil are mixed in the oil cooler 15 and the temperatures are averaged, the cooled oil cannot be sent to the oil pump 13 and the first oil pump 23. Would. Further, in the other oil cooling device of FIG. 3, the oil whose temperature has been averaged is cooled in the oil cooler 15, so that the cooling efficiency is reduced.

If the oil cannot be sufficiently cooled, the temperature of the oil sent to each actuator increases accordingly, and the amount of heat generated in each actuator cannot be sufficiently recovered.

An object of the present invention is to solve the problems of the conventional oil cooling device and to provide an oil cooling device which can be downsized and can sufficiently recover the amount of heat generated in the actuator. And

[0017]

For this purpose, in the oil cooling apparatus of the present invention, a low-temperature tank for storing cooled oil, a high-temperature tank for storing high-temperature return oil, and the low-temperature tank A first oil pump connected to the high-temperature tank and sucking oil in the low-temperature tank; and an actuator that is operated by receiving oil discharged from the first oil pump. A first circuit for draining into the tank, and a second circuit for connecting the low-temperature tank and the high-temperature tank and sucking oil in the high-temperature tank.
And a second circuit for draining the oil from the oil cooler to the low-temperature tank, comprising: an oil pump for cooling the oil discharged from the second oil pump.

In another oil cooling device according to the present invention, the low-temperature tank and the high-temperature tank are communicated by communication means.

In still another oil cooling device of the present invention,
Further, the low-temperature tank and the high-temperature tank are insulated by heat-insulating means.

[0020]

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

FIG. 1 is a conceptual diagram of an oil cooling device according to a first embodiment of the present invention.

In the drawing, reference numeral 30 denotes an oil tank, and 31 denotes a low-temperature tank 3 which partitions the inside of the oil tank 30 and stores cooled oil.
4, and a partition wall 32 as a partition member forming a high-temperature tank 35 for storing high-temperature return oil, a partition wall 32 is formed near the lower end of the oil tank 30 in the partition wall 31, and the low-temperature tank 34 and the high-temperature tank 35 A communication port as communication means for communicating. 43 is a first oil pump for generating a hydraulic pressure for operating the actuator 44, and 45 is an oil cooler 15
2 is a second oil pump for generating a hydraulic pressure for sending oil to the oil pump. Oil passage L-21, first oil pump 43, oil passage L-2
2. First by the actuator 44, the oil passage L-23, etc.
Circuit, the oil passage L-24, the second oil pump 45, the oil passage L
-25, the oil cooler 15, the oil passage L-26, etc., form a second circuit.

The actuator 44 is provided in a hydraulic circuit of a hydraulic injection molding machine, and includes an oil pump for generating a hydraulic pressure, a hydraulic motor for rotating a screw in an injection device, and a reciprocating screw. Or a mold clamping cylinder for operating a toggle mechanism in a mold clamping device.

In this case, when the first oil pump 43 is driven, the oil in the low-temperature tank 34 is sucked by the first oil pump 43 via the oil passage L-21 and passes through the oil passage L-22. Then, it is sent to the actuator 44, and after operating the actuator 44, it is drained to the high temperature tank 35 via the oil passage L-23. Then, when the second oil pump 45 is driven, the oil in the high-temperature tank 35 is sucked by the second oil pump 45 via the oil passage L-24, and the oil passage L-25.
To the oil cooler 15 and the oil cooler 1
After being cooled in 5, it is drained to the low-temperature tank 34 via the oil passage L- 26.

As described above, in order to operate the actuator 44, the oil in the low-temperature tank 34
And drained to the high-temperature tank 35, and the oil in the high-temperature tank 35 is sent to the oil cooler 15 to be cooled,
Since the oil is drained to the low-temperature tank 34, the high-temperature return oil and the cooled oil in the oil tank 30 can be stored in the low-temperature tank 34 and the high-temperature tank 35 without being mixed. Therefore, the cooled oil can be sent to the low-temperature tank 34, so that the oil in the low-temperature tank 34 can be sufficiently cooled and the high-temperature oil can be sent to the high-temperature tank 35. The temperature of the oil inside can be sufficiently increased, and the cooling efficiency of the oil cooler 15 can be improved.

By the way, as the size of the injection molding machine increases, the amount of heat generated in the actuator 44 increases. Therefore, if the capacity of the oil cooler 15 is increased in order to sufficiently cool the oil, it is necessary to increase the discharge amount of the second oil pump 45 in order to supply a sufficient amount of oil to the oil cooler 15. In addition, in order to supply a sufficient amount of cooling medium, for example, cooling water to the oil cooler 15, it is necessary to increase the discharge amount of a cooling medium pump (not shown). Therefore, the size of the oil cooling device increases accordingly.

However, in the present invention, as described above, the oil in the low-temperature tank 34 is sufficiently cooled and the high-temperature tank 3 is cooled.
Since the temperature of the oil in the oil cooler 15 is sufficiently raised, the second oil pump 45 is driven to suck the oil in the high-temperature tank 35 and send it to the oil cooler 15. And the temperature of the cooling water at the inlet side can be increased. Therefore, the heat exchange efficiency (cooling efficiency) of the oil cooler 15 can be increased. As a result, not only can the capacity of the oil cooler 15 be reduced, but also the amount of oil supplied to the oil cooler 15 and the amount of cooling water can be reduced, and the second oil pump 45 and the cooling medium pump Can be reduced.

Further, since the oil can be sufficiently cooled by the oil cooler 15, the temperature of the oil sent to the actuator 44 decreases accordingly, and the
Can be sufficiently recovered.

In this case, when the discharge amount of the second hydraulic pump 45 becomes smaller than the discharge amount of the first oil pump 43,
The amount of oil sucked from the high temperature tank 35 and drained to the low temperature tank 34 is smaller than the amount of oil sucked from the low temperature tank 34 and drained to the high temperature tank 35. Since the tank 35 is in communication, the oil levels in the low temperature tank 34 and the high temperature tank 35 are equal. Since the communication port 32 is formed near the lower end of the oil tank 30 in the partition wall 31, the temperature of the oil in the low-temperature tank 34 and the temperature of the oil in the high-temperature tank 35 are relatively close, and the temperature difference is small. small. Therefore, by the oil passing through the communication port 32,
It is possible to suppress an increase in the temperature of the cooled oil in the low-temperature tank 34 and a decrease in the temperature of the high-temperature return oil in the high-temperature tank 35.

Further, the first and second oil pumps 43, 4
5 can be equalized. In that case, since the amount of the cooled oil and the amount of the high-temperature return oil are equal, the amounts of the oil in the low-temperature tank 34 and the high-temperature tank 35 do not change. Therefore, the cross-sectional area of the communication port 32 is reduced,
The amount of oil passing through the communication port 32 can be reduced. As a result, the temperature of the oil in the low temperature tank 34 can be lowered, and the temperature of the oil in the high temperature tank 35 can be maintained high.

The first and second oil pumps 43, 4
5 is a variable discharge capacity type oil pump, and the discharge amount can be changed according to the fluctuation of the oil level in the low temperature tank 34 and the high temperature tank 35.

Next, a second embodiment of the present invention will be described.

FIG. 4 is a conceptual diagram of an oil cooling device according to a second embodiment of the present invention.

In this case, the inside of the oil tank 30 is partitioned by a partition member having a predetermined height and a partition wall 51 as a heat insulating means, and a low-temperature tank 34 for storing cooled oil and a high-temperature tank 34 for storing hot return oil. A tank 35 is formed. Since the partition wall 51 is formed of a material having a high heat insulating property and forms a heat insulating wall, heat is transferred between the cooled oil in the low-temperature tank 34 and the high-temperature return oil in the high-temperature tank 35. Without increasing the temperature of the oil in the low-temperature tank 34 or
The temperature of the oil in 5 does not decrease.

Since the discharge amount of the second hydraulic pump 45 is smaller than the discharge amount of the first oil pump 43, the amount of oil sucked from the high-temperature tank 35 and drained to the low-temperature tank 34 is low. The amount of oil sucked from the tank 34 and drained to the high temperature tank 35 becomes smaller, and the oil level in the low temperature tank 34 becomes lower than the oil level in the high temperature tank 35. And
When the level of oil in the high-temperature tank 35 becomes higher than the partition wall 51, the oil in the high-temperature tank 35 flows into the low-temperature tank 34. The upper end of the partition wall 51 constitutes a communicating means.

The oil passage L-21, the first oil pump 4
3, oil passage L-22, actuator 44, oil passage L-23
For example, the first circuit includes an oil passage L-24, a second oil pump 45, an oil passage L-25, an oil cooler 15, and an oil passage L-2.
6 and the like form a second circuit.

Next, a third embodiment of the present invention will be described.

FIG. 5 is a conceptual diagram of an oil cooling device according to a third embodiment of the present invention.

In this case, the inside of the oil tank 60 includes a low-temperature tank 54 for storing cooled oil and a high-temperature tank 55 for storing high-temperature return oil, which are communicated with each other by a communication passage 57 as communication means near the lower end. , Between the low-temperature tank 54 and the high-temperature tank 55, the heat-insulating air layer 5 mainly as a heat-insulating means.
6 are defined. Therefore, heat is hardly transferred between the cooled oil in the low-temperature tank 54 and the high-temperature return oil in the high-temperature tank 55, so that the temperature of the oil in the low-temperature tank 54 rises, A decrease in the temperature of the oil in 55 can be further suppressed.

The first circuit includes an oil passage L-24, a second oil pump 45, an oil passage L-21, a first oil pump 43, an oil passage L-22, an actuator 44, and an oil passage L-23. ,
A second circuit is configured by the oil passage L-25, the oil cooler 15, the oil passage L-26, and the like.

The present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0042]

As described above in detail, according to the present invention, in the oil cooling apparatus, a low-temperature tank for storing cooled oil, a high-temperature tank for storing high-temperature return oil, and the low-temperature tank A first oil pump connected to the tank and sucking oil in the low-temperature tank; and an actuator that is operated by receiving oil discharged from the first oil pump, and supplies the oil of the actuator to the high-temperature tank. A second circuit that connects the low-temperature tank and the high-temperature tank to each other, sucks oil in the high-temperature tank, and cools oil discharged from the second oil pump. And a second circuit for draining oil from the oil cooler to the low-temperature tank.

In this case, the oil in the low-temperature tank is sucked by the first oil pump, sent to the actuator and drained to the high-temperature tank, and the oil in the high-temperature tank is sucked by the second oil pump. Since the oil is sent to the cooler and drained to the low-temperature tank, the oil in the low-temperature tank can be sufficiently cooled. Therefore, when the second oil pump is driven to suck the oil in the high-temperature tank and send it to the oil cooler, the difference between the oil inlet temperature and the cooling medium inlet temperature in the oil cooler is increased. Therefore, the heat exchange efficiency in the oil cooler can be increased.

As a result, not only the capacity of the oil cooler can be reduced, but also the amount of the oil supplied to the oil cooler and the amount of the cooling medium can be reduced. The discharge amount of the pump can be reduced.

Further, since the oil can be sufficiently cooled by the oil cooler, the temperature of the oil sent to the actuator decreases accordingly, and the amount of heat generated in the actuator can be sufficiently recovered.

In another oil cooling device according to the present invention, the low-temperature tank and the high-temperature tank are communicated by communication means.

In this case, the oil level in the low temperature tank and the oil level in the high temperature tank can be equalized.

In still another oil cooling device of the present invention,
Further, the low-temperature tank and the high-temperature tank are insulated by heat-insulating means.

In this case, there is no heat transfer between the cooled oil in the low-temperature tank and the high-temperature return oil in the high-temperature tank, so that the temperature of the oil in the low-temperature tank rises, The temperature of the oil in the tank does not drop.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an oil cooling device according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram of a conventional oil cooling device.

FIG. 3 is a conceptual diagram of another conventional oil cooling device.

FIG. 4 is a conceptual diagram of an oil cooling device according to a second embodiment of the present invention.

FIG. 5 is a conceptual diagram of an oil cooling device according to a third embodiment of the present invention.

[Explanation of symbols]

 15 Oil cooler 32 Communication port 34, 54 Low temperature tank 35, 55 High temperature tank 43, 45 First and second oil pump 44 Actuator 51 Partition wall 56 Insulated air layer 57 Communication path L-21 to L-26 Oil path

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H082 AA06 AA25 CC02 DB08 DB37 EE05 4F206 AK02 AM19 AR067 JA07 JL02 JQ90 JT21

Claims (3)

[Claims] 1. A low-temperature tank for storing cooled oil,
(B) a high-temperature tank for storing high-temperature return oil, (c) a first oil pump that connects the low-temperature tank and the high-temperature tank and sucks oil in the low-temperature tank, and discharges the oil from the first oil pump. A first circuit that includes an actuator that is operated by receiving the applied oil, and that drains the oil of the actuator to the high-temperature tank;
(D) a second oil pump that connects the low-temperature tank and the high-temperature tank and sucks oil in the high-temperature tank; and an oil cooler that cools oil discharged from the second oil pump. A second circuit for draining oil from a cooler to the low-temperature tank. 2. The oil cooling device according to claim 1, wherein the low-temperature tank and the high-temperature tank are communicated by communication means. 3. The oil cooling device according to claim 1, wherein the low-temperature tank and the high-temperature tank are insulated by heat insulating means.