JPH0519735U - V type packing device - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] A space is provided between the packings, and the hydraulic pressure leaking from the front pushes the lip outwards, making proper contact with the seal against the shaft or housing. [Structure] V-shaped packings 38 and retainer rings 39 made of metal are alternately fitted and arranged. The V-shaped packing has the lip portion 38b in contact with the sliding shaft, the retainer ring has a diameter that does not contact the sliding shaft, and there are four pressure relief oil grooves on the inner peripheral surface on the sliding shaft side. 37a and 39a are engraved and arranged.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a V-type packing device used for a seal between a rotating or reciprocating motion shaft and a housing.

[0002]

[Prior Art]

 FIG. 9 shows a cross-sectional view in which conventional V-shaped packings are superposedly arranged. Conventionally, the packing used between the motion shaft 2 and the housing 1 is a V-shaped packing 3. Nitrile rubber, which has excellent oil resistance, is often used as the material for the V-shaped packing 3. When such V-shaped packing 3 is superposedly arranged as shown in FIG. The portion 3a is pressed and brought into close contact with the outer wall of the movement shaft 2.

[0003]

[Problems to be solved by the device]

 At this time, the pressing force applied to the inner diameter lip portion 3a increases or decreases due to the eccentricity of the movement shaft 2 and the shaft deviation, so that the inner diameter lip portion 3a is compressed and deformed. Under such a condition, the hydraulic pressure applied through the seal wall 5 is applied to the V-shaped packing 7 of the second stage by the compression deformation of the V-shaped packing 6 of the first stage, but the V-shaped packing of the third stage is applied. Since the packing 8 and later are less likely to be affected by hydraulic pressure, and the restoring force from compression deformation is weak, there is a drawback in that pressure fluid such as oil easily leaks.

The present invention has been made in view of the above problems, and a space is provided between each V-shaped packing, and hydraulic pressure leaked from the front presses the lip portions 3a and 3b outward, and the movement shaft 2 Or, the purpose is to make a proper close contact with the seal with respect to the housing 1.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, in the present invention, a packing having a V-shaped cross section and a metal retainer ring that fits with the above-mentioned packing are arranged in a superposed manner, and the retainer ring slides on the sliding shaft side. A groove is formed in the longitudinal direction on a part of the circumferential surface.

[0006]

[Action]

 In the vertical mold clamping device, when the movable mold attached to the movable platen and the fixed mold attached to the fixed platen are matched, the descending speed of the movable plate is gradually decreased, and finally the drain port When is blocked by the pullback ram, the movable platen stops descending, at which point the movable mold and the fixed mold come into contact, and the two molds are gently matched. When such an operation is repeated, the inner diameter lip of the V-shaped packing is deformed due to the eccentricity of the ram rod and the shaft deviation, but the V-shaped packing and the retainer ring are alternately arranged. Even if the V-shaped packing of the eye is deformed, oil leakage can be prevented with the V-shaped packing of the second stage.

[0007]

【Example】

 Hereinafter, specific embodiments of the V-shaped packing according to the present invention will be described in detail with reference to the drawings. 1 is a vertical cross-sectional view of the mold clamping device, FIG. 2 is a vertical cross-sectional view of the pullback cylinder, FIG. 3 is a cross-sectional view in which a V-shaped packing and a retainer ring are installed in the packing groove, and FIG. 4 is a perspective view of the retainer ring. 5 is a partial perspective view of the retainer ring, FIG. 6 is a sectional view taken along the line VI-VI of FIG. 4, FIG. 7 is a partial perspective view of the V-shaped retainer ring, and FIG. 8 is a sectional view taken along the line VIII-VIII of FIG. FIG. 9 and FIG. 9 are cross-sectional views in which a conventional V-shaped packing is mounted in a packing groove in a superimposed manner.

FIG. 1 illustrates a mold clamping device of a vertical injection molding device to which the V-shaped packing of the present invention is applied. In the figure, reference numeral 11 is a fixed platen on which a fixed mold 12 is fixed. A cylinder platen 13 is disposed above the stationary platen 11 and is connected to each other by four tie bars 14. A tank 15 is provided on the upper end of the cylinder platen 13, and a main ram 16 for mold clamping is slidably fitted inside the cylinder platen 13, and a movable plate 17 is integrated with the main ram 16. It is provided. The movable platen 17 is guided in a state of being slidably fitted to the tie bar 14, and a movable mold 18 is fixed to the lower surface.

Reference numeral 19 is a product extrusion device, and reference numeral 20 is a pull back cylinder device for mold opening. By the way, this pullback cylinder device 20 is shown enlarged in FIG. That is, the pullback cylinder device 20 is assembled based on the hollow pullpack cylinder 21. At the lower end of the pullback cylinder 21, a throttle portion 21a is formed inside. A plurality of oil drain ports 22 to 26 are opened in a line in the vertical direction at predetermined intervals so as to face the throttle portion 21a. Of the oil drain ports 22 to 26, throttles 27 to 30 are provided in the pipes connected in parallel to the second oil drain port 23 from the bottom to the uppermost oil drain port 26, respectively. In addition, a check valve 31 is provided in the pipe of the oil discharge port 22 in the lowermost stage. The pipes provided in parallel are connected to a hydraulic pressure supply source or a tank (not shown) by one pipe 35.

A pullback ram 33 is slidably fitted in the pullback cylinder 21, and a part of the pullback ram 33 extends outwardly above the pullback cylinder 21, and a ram rod 34 is provided inside the pullback ram 33. And penetrates through the pullback cylinder 21 and is fitted. A female screw 33a is formed on the inner surface of the pullback ram 33, and a male screw 34a formed on the upper end of the ram rod 34 over a certain length is screwed into the male screw 34a. Therefore, by rotating the pullback ram 33, the ram rod 34 and the pullback ram 33 adjust the above-mentioned screwed state to adjust the relative vertical positional relationship between the two, and to adjust the thickness of the attached mold. The position of the pullback ram 33 can be adjusted correspondingly.

High-pressure oil is stored in the pullback cylinder 21 described above, and a part of the pullback cylinder 21 is engraved in order to prevent oil leakage between the pullback cylinder 21 and the pullback ram 33. The V-shaped packing device 36 is incorporated in the packing groove formed by the above. The V-type packing device 36 includes an adapter retainer ring 37, a V-type packing 38, a V-type retainer ring 39, an adapter V-type packing 40, and a packing retainer 43.

The V-shaped packing 38 having a substantially V-shaped cross section is made of, for example, nitrite rubber having excellent oil resistance. The V-shaped packing 38 includes a base portion 38a located at the bottom of the V-shape, an inner diameter lip portion 38b and an outer diameter lip portion 38c located at the upper opening, and the inner diameter lip portion 38b includes the ram rod 34 and further the outer diameter lip portion. 38c are arranged so as to be in close contact with the pullback cylinders 21. Here, the V-shaped packing 38 may be made of oil-resistant styrene-butadiene rubber, chloroprene rubber, polysulfide rubber, or the like.

Retainer rings 37 and 39 are arranged so as to be able to hold the V-shaped packing 38 in a sandwiched manner. Two types of retainer rings 37 and 39 are used. An adapter retainer ring 37 located upstream of the pressure oil and a V-shaped retainer located downstream of the adapter and alternately fitted with the V-shaped packing 38 in a superimposed manner. Ring 39 is used. The retainer ring 37 for the adapter has a pentagonal shape, and the bottom portion 37b abuts the adjacent bush 41, and the heel portion 37c holds the above-mentioned fitted state of the V-shaped packing 38 and the V-shaped retainer ring 39. It is becoming like this.

On the other hand, the V-shaped retainer ring 39 has an inverted V-shaped recess 39b in the lower part, and the base 38a of the packing 38 is fitted into this recess 39b so that the packing 38 is seated in the normal position. Here, the inner diameter of the packing 38 (the end surface reference dimension of the inner diameter lip portion 38b) is smaller than the inner diameters of the adapter retainer ring 37 and the V-shaped retainer ring 39. That is, the retainer ring 37 for adapter and the V-shaped retainer ring 39 have almost the same inner diameter, and when they are inserted into the ram rod 34, a slight clearance is generated between the ram rod 34 and the retainer rings 37, 39. It is like this.

Further, four pressure relief grooves 37a, 39a are provided on the inner peripheral surfaces of the adapter retainer ring 37 and the V-shaped retainer ring 39 at equal intervals. This is configured so that pressure oil can be transmitted from the upstream side and pressure can be uniformly released from the inner diameter lip 38b side. As a result of these measures, there is no leakage of hydraulic pressure from the upstream side, and there is no unnecessary deformation of the V-shaped packing 38, so there is no leakage of oil to the outside. Both the adapter retainer ring 37 and the V-shaped retainer ring 39 are molded from metal, for example, brass.

Reference numeral 40 is a V-shaped packing for an adapter formed of the same material as the V-shaped packing 38. The sealing packing 36 is pressed by the packing pressing ring 43 through the presser foot 42, and the bolt 44 is used. It is fixed. In addition, 45 indicates a normal plate packing.

Next, the operation of the above embodiment will be described. _{D 1} the outer diameter of the pull-back ram 33, diaphragm Ri portion 21a inside diameter _{d 2} of, when _{d 3} the outer diameter of the push rod 34, the relationship between them becomes _d 3 _<d 1 _{<d 2.} The inner diameter d ₂ of the throttle portion 21a is smaller than the outer diameter d ₁ of the pullback ram 33 by, for example, 0. The inner diameter was slightly larger, such as several mm. As the pull-back ram 33 descends, the lower end of the pull-back ram 33 begins to block from the upper oil discharge port in the order 26, 25, 24, etc., and the amount of oil discharged from the pull-back cylinder 21 sequentially. When the movable plate 17 is lowered, the descending speed of the movable plate 17 is gradually decreased, and when the oil drain port 22 is finally closed by the pullback ram 33, the movable plate 17, and hence the movable mold 18, stops descending and the movable mold 17 is stopped. The mold 18 and the fixed mold 12 are gently fitted together, and then the mold is clamped and a molten resin is injected into the mold cavity from an injection molding machine (not shown).

When such an operation is repeated many times, the pressure oil from the upstream side, that is, the pullback cylinder 21 is applied to the inner diameter lip portion 38b of the V-shaped packing 38 due to the eccentricity of the ram rod 34 and the shaft deviation. The pressing force is exacerbated, the inner diameter lip portion 38b is deformed, and oil leakage occurs.

In the present embodiment, even when the first-stage V-shaped packing 38 is deformed and the hydraulic pressure leaks, the oil passes through the pressure relief groove 39 a of the retainer ring 39 and the second-stage V-shaped packing 38. The kin 38 is reached, where pressure is newly applied to the inner diameter lip portion 38b. This pressure acts as a pressing force that pushes the inner diameter lip portion 38b outward, so that the inner diameter lip portion 38b can be brought into closer contact with the pullback ram 33 to prevent oil leakage. In this embodiment, since the V-shaped packing 38 is arranged in three steps at regular intervals, even if there is an oil leak in the above-mentioned second step, the same V-type packing 38 in the third step is used. Oil leakage can be prevented. In the present embodiment, the V-shaped packing 38 and the V-shaped retainer ring 39 are alternately fitted and arranged in a superimposed manner. However, the present invention is not limited to this, and the V-shaped packing 38 is doubled. It is also possible that one set is fitted and a retainer ring is fitted between the one set of V-shaped packings.

[0020]

[Effect of the device]

 As is clear from the above description, in the present invention, a packing having a V-shaped cross section and a metal retainer ring that fits with the packing are arranged in an overlapping manner, and the retainer ring slides. By providing a groove in the longitudinal direction on a part of the circumferential surface on the shaft side, the sealing performance is improved and the lubrication effect is promoted, so that the life of the V-type packing can be extended and the external Oil leakage is completely prevented.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a mold clamping device to which a V-shaped packing according to an embodiment of the present invention is applied.

FIG. 2 is a vertical sectional view of a pullback ram cylinder.

FIG. 3 is a sectional view in which a V-shaped packing and a retainer ring are mounted in a packing groove.

FIG. 4 is a perspective view of a retainer ring.

FIG. 5 is a partial perspective view of a retainer ring for an adapter.

6 is a cross-sectional view as seen from VI-VI in FIG.

FIG. 7 is a partial perspective view of a V-shaped retainer ring.

8 is a cross-sectional view as seen from VIII-VIII in FIG. 7.

FIG. 9 is a cross-sectional view in which a conventional V-shaped packing is mounted in a packing groove in a superimposed manner.

[Explanation of symbols]

 11 Fixed Plate 14 Tie Bar 17 Movable Plate 20 Pullback Cylinder Device 21 Pullback Cylinder 33 Pullback Ram 34 Ram Rod 36 Packing Device 37 Adapter Retainer Ring 37a, 39a Pressure Release Groove 38 V-shaped Packing 38a Base 38b Inner Diameter Lip 38c Outer Diameter Lip 39 V type retainer ring 40 V type packing for adapter 41 Bush

Claims (1)

[Scope of utility model registration request] 1. A packing having a V-shaped cross section and a metal retainer ring that fits with the packing are arranged in a superimposed manner, and the retainer ring is longitudinally provided on a part of a circumferential surface on the sliding shaft side. A V-type packing device characterized in that a groove engraved in the direction is provided.