JPH11314257A - Hydraulic pressure generation device for injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a more effective heat countermeasure technique of a hydraulic pressure generating device. SOLUTION: Heat of an electric motor flows to a motor housing 33 as shown by arrows (1), (1) and then the same reaches a refrigerant passage 25 through both the front flange 32 and a collar 31 as shown by arrows (2), (2) and is absorbed by a refrigerant. Thereby, heat generation of the motor is absorbed by the refrigerant through a bracket and discharged outside of an injection molding machine. Accordingly, even if a hydraulic generation device is arranged in the inside of the bed of the molding machine in bad conditions, the electric motor is efficiently cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for countermeasures against heat in a hydraulic pressure generator of an injection molding machine.

[0002]

2. Description of the Related Art FIG. 5 is a front view of a conventional injection molding machine. In an injection molding machine 100, an injection device 102 and a mold clamping device 103 are mounted on an upper surface of a molding machine bed 101.
3 is a machine for manufacturing a resin molded product by injection-filling a resin plasticized and melted by an injection device 102 into a mold (not shown) in a mold 3.
In general, moving the injection device 102 back and forth with respect to the mold clamping device 103, rotating a screw in the injection device 102,
All or part of the movement of the shaft, the driving of the mold clamping device 103, and the like are performed by hydraulic pressure. An example in which the hydraulic pressure generating device 110 for that purpose is housed in the internal space of the molding machine bed 101 is shown. Hydraulic pressure generating device 110 is a molding machine bed 101
There is a case where it is stored inside or a case where it is placed outside. The storage inside the molding machine bed 101 is preferably adopted because the hydraulic piping is not exposed and the floor area can be reduced. At this time, the motor support is the molding machine bed 101.

FIG. 6 is a front view of a conventional hydraulic pressure generating device. In a hydraulic pressure generating device 110, an electric motor 113 and a hydraulic pump 114 are mounted on a bracket 111 via a flanged sleeve 112, and both shafts are cup-connected. Ring 11
5 and the hydraulic pump 114 is driven by the electric motor 113.

The electric motor 113 is a means for converting electric energy into rotational energy, and it is known that various kinds of losses called iron loss and copper loss occur in the form of heat. That is, the electric motor 113 is a kind of heater, and its heat is basically released to the surrounding air or the like. If the surrounding temperature is high, the temperature of the electric motor 113 itself increases.

Since the allowable temperature of the electric motor 113 is determined by the built-in insulation, it is significantly affected by the operating temperature. The higher the operating temperature, the shorter the life. Therefore, a cooling fan 116 is attached to the end of the motor shaft, and the motor housing 117 is forcibly cooled by the air generated by the cooling fan 116 to reduce the operating temperature of the electric motor 113.

[0006]

In recent years, the demand for speeding up an injection molding machine has increased the discharge flow rate and discharge pressure of a hydraulic pressure generator, and the heat generation has increased accordingly. In the above method of forcibly cooling the motor housing with a cooling fan,
It is necessary to take measures such as increasing the cooling fan and increasing the motor model number. In some cases, a hydraulic pressure generator is mounted on an oil tank attached to an injection molding machine. The oil tank stores warm oil, so the temperature tends to rise.

However, when the hydraulic pressure generator is housed inside the molding machine bed, the air stays inside the molding machine bed, so that the temperature of the air inside the molding machine bed rises and the cooling capacity decreases. Therefore, the above measures are not so effective. Also, when the oil pressure generator is mounted on the oil tank, the temperature of the air around the oil tank rises,
Cooling capacity decreases. Therefore, the above measures are not so effective. Therefore, an object of the present invention is to provide a more effective heat countermeasure technology for a hydraulic pressure generator.

[0008]

Means for Solving the Problems To solve the above problems, a first aspect of the present invention is a hydraulic pump for generating a hydraulic pressure required for operation of an injection molding machine, an electric motor for driving the hydraulic pump, and an electric motor for the electric motor. And a bracket that attaches the motor to the motor support.In the hydraulic pressure generating device, a coolant passage is provided in the bracket to provide an internal cooling bracket, and this bracket is brought into contact with the motor housing to conduct heat generated by the motor to the bracket. It is characterized in that it is made to be.

The heat generated by the motor is absorbed by the coolant through the bracket and discharged to the outside of the injection molding machine. Therefore, the electric motor can be efficiently cooled even if the hydraulic pressure generating device is arranged inside the molding machine bed or the oil tank under poor conditions.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. FIG. 1 is a front view of a hydraulic pressure generating device according to the present invention.
(Hereinafter simply referred to as “bracket 10”), a sleeve 11 with a flange, an electric motor 12, and a hydraulic pump 13. The electric motor 12 is a servo motor without a cooling fan. The hydraulic pump 13 is a general-purpose hydraulic pump such as a swash plate type piston pump, a plunger pump, a vane pump, and a gear pump.

FIG. 2 is an exploded perspective view of a main part of the hydraulic pressure generating device according to the present invention, and the bracket 10 has bolt holes 21.
・ (... indicates a plurality. The same applies to the following.)
2, 22 and a relatively thick vertical plate 24 having a hole 23, and the vertical plate 24 is provided with refrigerant passages 25, 25. 26 is a refrigerant inlet, 27 is a refrigerant outlet, 2
8, 29 are large and small O-rings. Insert the flanged sleeve 11 into the hole 23 of the vertical plate 24, and set the O
The flange 31 is attached to the vertical plate 24 so as to sandwich the rings 28 and 29.
On the front flange 32 of the electric motor 12
Then, the vertical plate 24, the flange 31, and the front flange 32 are tightened up by a long bolt (not shown) to be integrated.

FIG. 3 is an assembled sectional view of the bracket, the flanged sleeve and the electric motor according to the present invention. The outside of the refrigerant passage 25 is sealed with an O-ring 28 and the inside of the refrigerant passage 25 is sealed with an O-ring 29. Thereby, leakage of the refrigerant can be prevented. Although a detailed description is omitted, the attachment of the electric motor 12 and the hydraulic pump 13 to the bracket 10 can be completed by attaching the hydraulic pump 13 to the distal end (the left end in the figure) of the flanged sleeve 11.

FIG. 4 is a view taken in the direction of arrows 4-4 in FIG. 3, and shows that one-stroke-shaped refrigerant passages 25, 25 are formed in the vertical plate 24. To be precise, these refrigerant passages 25, 25 are shown. Is a groove, and is covered with a flange (see reference numeral 31 in FIG. 3).
The passage is completed. Since it is a groove, it can be easily cut with a machine tool.

The operation of the above-described hydraulic pressure generator will be described below. In FIG. 3, heat generated by the electric motor 12 flows through the motor housing 33 as indicated by an arrow, reaches the refrigerant passage 25 via the front flange 32 and the flange 31 as indicated by the arrow, and is absorbed by the refrigerant. The coolant is preferably cooling water for cooling a mold and a material drop opening, cooling water for cooling hydraulic oil, hydraulic oil used in a hydraulic device, and compressed air. In any case, since the refrigerant is pressure-fed from the outside to the refrigerant passage 25 and is forcibly recovered, the flow velocity can be increased. The heat recovery amount increases as the inlet temperature of the refrigerant decreases, and increases as the flow velocity of the refrigerant increases. Therefore, a large amount of heat can be taken if the refrigerant is pressure-fed while being cooled by an appropriate refrigerator.

Next, the thermal characteristics of the members in the heat conduction path will be examined. In FIG. 3, the motor housing 33, the flange 3
1. Since the bracket 10 corresponds to a heat conducting member, the larger the heat conductivity, the better. The thermal conductivity of carbon steel is 45 k
cal / mh ° C, the thermal conductivity of cast iron is 51 kcal /
mh ° C, the thermal conductivity of aluminum is 196 kcal
/ Mh ° C, the thermal conductivity of copper is 332 kcal / mh ° C
It is. However, aluminum and copper have low mechanical strength. When a high-strength aluminum alloy or a high-strength copper alloy is used to increase the strength, the thermal conductivity decreases.

In this embodiment, the refrigerant is in direct contact with the flange 31, and the flange 31 is an intermediate flange of a so-called three-flange. Therefore, the bracket 10 is made of carbon steel, the flange 31 is made of copper or aluminum, and the motor housing 33 is made of cast iron or carbon steel. Or preferably, the bracket 10 is made of an aluminum alloy, the flange 31 is made of copper or aluminum, and the motor housing 3
3 is made of aluminum. Alternatively, only the vertical plate described with reference to FIG. 2 may be made of a good heat conductive material, and the brackets 10 may be made of a combination of different metals, such as the legs 22 and 22 made of carbon steel.

Even if the hydraulic pressure generator 1 of the present invention is housed in the molding machine bed 101 of FIG. 5 or mounted on an oil tank (not shown), heat can be discharged to the outside of the machine together with the refrigerant, so that a thermal trouble occurs. There is no need to worry, the operating conditions of the electric motor can be strict, and the frame number of the electric motor can be reduced.

The hydraulic pressure generating device 1 according to the present invention is also effective when it is placed separately from the injection molding machine 100. Further, the shape and number of the coolant passages 25 are arbitrary. Further, the brackets 10 may be cast, and the coolant passages 25 may be integrally formed at the casting stage using a core. In FIG.
Is omitted, and the motor housing 33 is directly attached to the bracket 10.
May be used.

From the mounting mode, the electric motor includes a flange type motor having a front flange and a so-called stationary type motor having a leg on a central lower surface of a horizontal motor housing. In the case of the stationary motor, the motor is mounted on the bracket, and the lower leg in the center directly contacts the bracket. At this time, the heat of the motor flows to the bracket via the legs.

As described above, heat only needs to be transmitted from the motor housing to the bracket side, so that the bracket only needs to be in contact with any part of the motor housing. Therefore, claim 1
In this case, the bracket may be in contact with the motor housing directly or via a good heat conducting material such as the flange.
In addition, the motor support of claim 1 may be any of a machine forming an injection molding machine, in addition to a molding machine bed and an oil tank, and the present invention is particularly applicable to a motor support where ambient air temperature tends to rise. It is valid.

[0021]

According to the present invention, the following effects are exhibited by the above configuration. According to the first aspect, the heat generated by the motor can be absorbed by the refrigerant through the bracket and discharged to the outside of the injection molding machine, and the heat can be efficiently removed without being affected by the ambient temperature. Can be. Therefore, the electric motor can be efficiently cooled, for example, even when the hydraulic pressure generating device is disposed inside the molding machine bed or in the oil tank.

[Brief description of the drawings]

FIG. 1 is a front view of a hydraulic pressure generating device according to the present invention.

FIG. 2 is an exploded perspective view of a main part of the hydraulic pressure generating device according to the present invention.

FIG. 3 is an assembled sectional view of the bracket, the flanged sleeve, and the electric motor of the present invention.

FIG. 4 is a view taken in the direction of arrows 4-4 in FIG. 3;

FIG. 5 is a front view of a conventional injection molding machine.

FIG. 6 is a front view of a conventional hydraulic pressure generator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Hydraulic pressure generator, 10 ... Internal cooling type bracket (bracket), 11 ... Sleeve with a flange, 12 ... Electric motor,
13: hydraulic pump, 25: refrigerant passage, 26: refrigerant inlet,
27: refrigerant outlet, 33: motor housing, 100: injection molding machine, 101: motor support (molding machine bed).

Claims (1)

[Claims] 1. A hydraulic pressure generating device comprising: a hydraulic pump for generating a hydraulic pressure required for operating an injection molding machine; an electric motor for driving the hydraulic pump; and a bracket for attaching the electric motor to a motor support. A hydraulic passage for an injection molding machine, wherein a coolant passage is provided in the bracket to allow a coolant to pass therethrough to form an internally cooled bracket, and the bracket is brought into contact with a motor housing to conduct heat generated by the motor to the bracket. apparatus.