Ejector pin device and injection molding machine
By designing a combination of control valves and other hydraulic valves in the injection molding machine's thimble device, the problem of speed loss and noise during thimble reset is solved, and a smoother and more stable thimble movement is achieved.
Patent Information
- Application Number
- CN202421561575.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-03
- Publication Date
- 2025-04-25
- Estimated Expiration
- 2034-07-03
AI Technical Summary
When the thimble is reset, the cylinder piston speed is out of control due to the external load, resulting in noise and shock vibration.
A thimble device is designed, including a thimble, a cylinder, a piston, a first oil circuit and a control valve. By providing a control valve on the first oil path, the piston retracts back pressure to the medium in the first chamber to provide motion resistance and avoid crawling. Through the combination of sequential valve, bypass check valve, locking check valve and spring, the outflow and inflow of the medium are ensured to be stable and noise and shock vibration are avoided.
Under the action of external load, the thimble cylinder maintains the expected working speed, avoids noise and shock vibration, and improves the stability and stability of the thimble movement.
Smart Images
Figure CN222792676U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of injection molding machines, in particular to an ejector device and an injection molding machine. Background Art
[0002] An injection molding machine is a mechanical device used to form plastic products. It heats and injects plastic material into a mold, which then cools to form the desired plastic product.
[0003] The ejector pin is a demolding mechanism on an injection molding machine, used to eject plastic products from the mold after molding. When the ejector pin is reset, the hydraulic control valve opens the oil circuit. Due to the external load, the ejector cylinder loses speed control, causing the piston to strike the cylinder wall and generate noise.
[0004] Therefore, it is necessary to develop a novel ejector device and injection molding machine to improve the above-mentioned problems existing in the prior art. Utility Model Content
[0005] The utility model aims to provide an ejector device and an injection molding machine, which can maintain an expected working speed of the ejector oil cylinder under the action of an external load when the ejector is retracted and reset.
[0006] The purpose of the utility model can be achieved through the following technical solutions:
[0007] The utility model provides an ejector device, comprising: an ejector, a cylinder, a piston, a first oil circuit, and a control valve; the piston is disposed in the cylinder and connected to the ejector, and together with the wall of the cylinder forms a first chamber for driving the ejector of an injection molding machine to extend and retract; the first oil circuit is connected to the first chamber; wherein the first oil circuit is provided with a control valve for applying back pressure to a medium flowing out of the first chamber when the ejector retracts and the piston moves toward one side of the first chamber.
[0008] Optionally, the piston and the cylinder together form a second chamber, the first chamber and the second chamber are located on both sides of the piston, and the second chamber is connected through a second oil circuit, wherein a spring is provided in the second chamber for applying back pressure to the medium flowing into the first chamber when the piston moves toward the side of the second chamber.
[0009] Optionally, the ejector device further includes a bypass one-way valve, which is connected to both ends of the control valve and is used to conduct the first oil circuit to move the piston toward the second chamber to extend the ejector.
[0010] Optionally, the ejector device further includes a first locking one-way valve and a second locking one-way valve, which are respectively arranged in the first oil circuit and the second oil circuit, and the control valve is arranged between the first chamber and the first locking one-way valve.
[0011] Optionally, the first oil circuit is connected to the control oil circuit of the second locking one-way valve, and the second oil circuit is connected to the control oil circuit of the first locking one-way valve.
[0012] Optionally, the first locking one-way valve and the second locking one-way valve are hydraulically controlled one-way valves, and the back pressure of the medium flowing out of or into the first chamber is respectively greater than the threshold pressure of the control oil circuit of the first locking one-way valve and the second locking one-way valve.
[0013] Optionally, the ejector device further includes a three-position four-way reversing valve, and the first oil circuit and the second oil circuit are connected to the three-position four-way reversing valve.
[0014] Optionally, the first oil circuit and the second oil circuit are connected to the oil tank through the middle position of the three-position four-way reversing valve.
[0015] Optionally, the control valve is a sequence valve.
[0016] The injection molding machine provided by the utility model comprises the above-mentioned ejector device.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
[0018] 1. In the utility model, when the ejector pin retracts and returns to its original position, the piston moves toward the side of the first chamber, and the medium in the first chamber flows out through the first oil circuit. By providing a control valve on the first oil circuit, back pressure is applied to the medium flowing out of the first chamber, providing the piston with a certain movement resistance, avoiding creeping, and making the ejector pin move more smoothly.
[0019] 2. The utility model forms back pressure on the medium flowing out of the first chamber by arranging the sequence valve in the first oil circuit. Since the structure of the sequence valve determines that it has the characteristic of being conductive only when the pressure is greater than a predetermined value, it can not only keep the back pressure stably at the predetermined value, but also the influence of external temperature is almost negligible, which is conducive to achieving movement stability and low cost.
[0020] 3. The utility model connects the bypass check valve to both ends of the control valve. When the ejector pin needs to be extended, the combination of the first oil circuit and the bypass check valve can transmit the medium to the first chamber by bypassing the control valve. When the ejector pin needs to be retracted, the control valve can cause the medium in the first chamber to flow out while providing a certain back pressure, thereby realizing the bidirectional extension and retraction function of the ejector pin.
[0021] 4. The utility model applies a certain back pressure when the medium flows out of and into the first chamber by providing a spring or a control valve, and makes the back pressure greater than the threshold pressure required for the control oil circuits of the first locking check valve and the second locking check valve to trigger reverse conduction, so that when the first oil circuit supplies the medium to the first chamber, the second locking check valve on the second oil circuit can be stably conducted, and when the second oil circuit supplies the medium to the second chamber, the first locking check valve on the first oil circuit can be stably conducted, thereby avoiding frequent switching of the first oil circuit or the second oil circuit between the conducting state and the blocking state due to unstable back pressure, which causes strong impact vibration and noise. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 Schematic diagram of the structure of the ejector device in the embodiment of the present utility model.
[0023] Reference numerals:
[0024] 1. Cylinder; 101. First chamber; 102. Second chamber; 2. Piston; 3. First oil circuit; 4. Second oil circuit; 5. Control valve; 6. Spring; 7. Bypass check valve; 801. First locking check valve; 802. Second locking check valve; 9. Three-position four-way reversing valve. DETAILED DESCRIPTION
[0025] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.
[0026] In some embodiments of the present invention, Figure 1 The ejector device includes: an ejector, a cylinder 1, a piston 2, a first oil circuit 3 and a control valve 5; the piston 2 is arranged in the cylinder 1 and connected to the ejector, and together with the wall of the cylinder 1 forms a first chamber 101 for driving the ejector of the injection molding machine to retract and extend; the first oil circuit 3 is connected to the first chamber 101; wherein, the first oil circuit 3 is provided with a control valve 5 for applying back pressure to the medium flowing out of the first chamber 101 when the ejector retracts and the piston 2 moves toward the side of the first chamber 101.
[0027] In some specific embodiments, the ejector pin includes a plurality of rods for ejecting the plastic product from the mold after injection molding.
[0028] In some specific embodiments, the control valve 5 can be a valve that is turned on after the mechanical parts on the path are pushed open by the pressure formed by the inflowing medium, and when turned on, it stably provides the medium with a back pressure equal to the resistance value formed by the mechanical parts.
[0029] In other specific embodiments, the control valve 5 may provide back pressure to the medium by changing the flow rate of the medium flowing through.
[0030] In some specific embodiments, the control valve 5 may be a relief valve, a sequence valve, a throttle valve, a speed regulating valve or a proportional valve, but the present invention is not limited thereto.
[0031] In some specific embodiments, referring to Figure 1 The medium flows into or out of the first chamber 101, exerting a force on the piston 2, so that the piston 2 drives the ejector pin to extend and retract.
[0032] In some specific embodiments, referring to Figure 1 , hydraulic oil is supplied to or discharged from the first chamber 101 through the first oil circuit 3 .
[0033] In some embodiments of the present invention, Figure 1 The piston 2 and the cylinder 1 together form a second chamber 102, the first chamber 101 and the second chamber 102 are located on both sides of the piston 2, and the second chamber 102 is connected through a second oil circuit 4, wherein a spring 6 is provided in the second chamber 102 for applying back pressure to the medium flowing into the first chamber 101 when the piston 2 moves toward the side of the second chamber 102.
[0034] In some specific embodiments, referring to Figure 1 When the medium flows into the first chamber 101 and flows out of the second chamber 102, or when the medium flows into the second chamber 102 and flows out of the first chamber 101, a force is applied to the piston 2, so that the piston 2 drives the ejector pin to extend and retract.
[0035] In some specific embodiments, hydraulic oil is supplied to or discharged from the second chamber 102 through the second oil passage 4 .
[0036] In some specific embodiments, referring to Figure 1 The expansion and contraction direction of the spring 6 is the moving direction of the piston 2, that is, the horizontal direction as shown in the figure. When the piston 2 moves to the right as shown in the figure, the piston 2 squeezes the spring 6, thereby causing the medium flowing into the first chamber 101 to be subjected to resistance, that is, the back pressure.
[0037] In some specific embodiments, referring to Figure 1 The first chamber 101 is connected to the first oil circuit 3 , and the back pressure acts on the media in the first chamber 101 and the first oil circuit 3 at the same time.
[0038] In some specific embodiments, referring to Figure 1When the second oil circuit 4 delivers hydraulic oil to the second chamber 102, a force is applied to the piston 2. The piston 2 moves to cause the medium in the first chamber 101 to flow out through the first oil circuit 3. The control valve 5 applies back pressure to the medium flowing out of the first chamber 101. At this time, the back pressure acts on the piston 2 through the first oil circuit 3 and the medium in the first chamber 101, so that the movement of the piston 2 encounters resistance, and then acts on the medium flowing into the second chamber 102 from the second oil circuit 4, so that the medium flowing into the second chamber 102 is subjected to back pressure.
[0039] In some embodiments of the present invention, Figure 1 The ejector device further includes a bypass one-way valve 7, which is connected to both ends of the control valve 5 and is used to conduct the first oil circuit 3 to move the piston 2 toward the second chamber 102 to extend the ejector.
[0040] In some specific embodiments, referring to Figure 1 The bypass one-way valve 7 is connected to both ends of the control valve 5 through a pipeline. The bypass one-way valve 7 is conductive in the flow direction of conveying the medium to the first chamber 101, so that the medium bypasses the control valve 5 and enters the first chamber 101.
[0041] In some specific embodiments, referring to Figure 1 The bypass one-way valve 7 is cut off in the flow direction of the medium out of the first chamber 101, so that the medium pressure in the pipeline reaches a predetermined value and then flows out of the first chamber 101 through the control valve 5 on the first oil circuit 3.
[0042] In some embodiments of the present invention, Figure 1 The ejector device also includes a first locking one-way valve 801 and a second locking one-way valve 802, which are respectively arranged in the first oil circuit 3 and the second oil circuit 4, and the control valve 5 is arranged between the first chamber 101 and the first locking one-way valve 801.
[0043] In some specific embodiments, referring to Figure 1 The first locking one-way valve 801 is closed in the direction in which the medium flows out of the first chamber 101, and the second locking one-way valve 802 is closed in the direction in which the medium flows out of the second chamber 102. When the ejector pin needs to maintain a specific position, the first locking one-way valve 801 and the second locking one-way valve 802 cut off the flow of the first oil circuit 3 and the second oil circuit 4. The medium in the first chamber 101 and the second chamber 102 does not flow, the piston 2 stops moving, and the position of the ejector pin is maintained.
[0044] In some embodiments of the present invention, Figure 1The first oil circuit 3 is connected to the control oil circuit of the second locking one-way valve 802 , and the second oil circuit 4 is connected to the control oil circuit of the first locking one-way valve 801 .
[0045] In some embodiments of the present invention, Figure 1 The first locking one-way valve 801 and the second locking one-way valve 802 are hydraulically controlled one-way valves, and the back pressure of the medium flowing out of and into the first chamber 101 is respectively greater than the threshold pressure of the control oil circuit of the first locking one-way valve 801 and the second locking one-way valve 802.
[0046] In some specific embodiments, referring to Figure 1 When the first oil circuit 3 transports medium to the first chamber 101, the medium passes through the first locking check valve 801 and bypasses the control valve 5 through the bypass check valve 7 to enter the first chamber 101. The spring 6 applies movement resistance to the piston 2, causing back pressure to form during the flow of the medium in the first oil circuit 3. The magnitude of the back pressure is greater than the threshold pressure of the control oil circuit of the second locking check valve 802, causing the second locking check valve 802 to be reversed, and the medium in the second chamber 102 to flow out through the second oil circuit 4.
[0047] In some specific embodiments, referring to Figure 1 When the second oil circuit 4 transports the medium to the second chamber 102, the medium flows into the second chamber 102 through the second locking check valve 802. In the initial stage, the control valve 5 blocks the first oil circuit, and the medium in the first chamber 101 cannot flow and exerts movement resistance on the piston 2, so that back pressure is generated during the flow of the medium in the second oil circuit 4. The magnitude of the back pressure is greater than the threshold pressure of the control oil circuit of the first locking check valve 801, causing the first locking check valve 801 to be reversed. Then, as the pressure of the medium in the first chamber 101 and the first oil circuit 3 exceeds the conduction pressure of the control valve 5, the control valve 5 is conducted, and the medium in the first chamber 101 flows out through the first oil circuit 3.
[0048] In some embodiments of the present invention, Figure 1 The ejector device further includes a three-position four-way reversing valve 9 , and the first oil circuit 3 and the second oil circuit 4 are connected to the three-position four-way reversing valve 9 .
[0049] In some embodiments of the present invention, Figure 1 The first oil circuit 3 and the second oil circuit 4 are connected to the oil tank through the middle position of the three-position four-way reversing valve 9.
[0050] In some specific embodiments, referring to Figure 1When the three-position four-way reversing valve 9 is in the middle position, the first oil circuit 3 and the second oil circuit 4 are connected to the oil return port.
[0051] In some embodiments of the present invention, Figure 1 , the control valve 5 is a sequence valve.
[0052] An embodiment of the present utility model provides an injection molding machine, which includes the above-mentioned ejector device.
[0053] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art based on the concepts of the present invention through logical analysis, reasoning, or limited experimentation based on the existing technology should be within the scope of protection defined by the claims.
Claims
1. A ejector device, characterized in that: include: thimble; Cylinder (1); A piston (2) is disposed in the cylinder (1) and connected to the ejector pin, and together with the wall surface of the cylinder (1) forms a first chamber (101) for driving the ejector pin of the injection molding machine to extend and retract; A first oil circuit (3), connected to the first chamber (101); The first oil circuit (3) is provided with a control valve (5) for applying back pressure to the medium flowing out of the first chamber (101) when the ejector pin is retracted and the piston (2) moves toward the first chamber (101).
2. The ejector device according to claim 1, characterized in that: The piston (2) and the cylinder (1) together form a second chamber (102); the first chamber (101) and the second chamber (102) are located on both sides of the piston (2); the second chamber (102) is connected via a second oil circuit (4); a spring (6) is provided in the second chamber (102) for applying back pressure to a medium flowing into the first chamber (101) when the piston (2) moves toward the second chamber (102).
3. The ejector device according to claim 2, characterized in that: It also includes a bypass one-way valve (7), which is connected to both ends of the control valve (5) and is used to conduct the first oil circuit (3) to move the piston (2) toward the second chamber (102) to extend the ejector pin.
4. The ejector device according to claim 2, characterized in that: It also includes a first locking check valve (801) and a second locking check valve (802), which are respectively arranged in the first oil circuit (3) and the second oil circuit (4), and the control valve (5) is arranged between the first chamber (101) and the first locking check valve (801).
5. The ejector device according to claim 4, characterized in that: The first oil circuit (3) is connected to the control oil circuit of the second locking check valve (802), and the second oil circuit (4) is connected to the control oil circuit of the first locking check valve (801).
6. The ejector device according to claim 5, characterized in that: The first locking check valve (801) and the second locking check valve (802) are hydraulically controlled check valves, and the back pressure of the medium flowing out of and flowing into the first chamber (101) is respectively greater than the threshold pressure of the control oil circuit of the first locking check valve (801) and the second locking check valve (802).
7. The ejector device according to claim 5, characterized in that: It also comprises a three-position four-way reversing valve (9), and the first oil circuit (3) and the second oil circuit (4) are connected to the three-position four-way reversing valve (9).
8. The ejector device according to claim 7, characterized in that: The first oil circuit (3) and the second oil circuit (4) are connected to the oil tank via the middle position of the three-position four-way reversing valve (9).
9. The ejector device according to claim 1, characterized in that: The control valve (5) is a sequence valve.
10. An injection molding machine, characterized in that: The invention comprises the ejector pin device according to any one of claims 1 to 9.