Wax injection head of wax injection machine

Abstract

The utility model relates to a wax injection head of a wax injection machine. The syringe comprises a first sleeve and a second sleeve, a trapezoidal annular gasket is arranged at the inner end of the first sleeve, a telescopic pipe is sleeved with the second sleeve, a plug fixedly connected with the telescopic pipe is arranged in the first sleeve, an injection cavity is formed in the telescopic pipe, a through hole penetrating through the inside and the outside is formed in the end, close to the plug, of the telescopic pipe, and a butt joint part is arranged at the head of the telescopic pipe. A reset spring is arranged between the butt joint part and the second sleeve, the first sleeve is provided with a sub-runner communicated with an inner cavity of the first sleeve, the sub-runner is connected with a buffer container, a piston is arranged in the buffer container, and the inner cavity of the buffer container is divided into an air cavity and a liquid cavity by the piston. The buffer liner is additionally arranged on the first sleeve, when the hydraulic pressure of wax liquid changes, the compressible property of air in the air cavity is utilized, the pressure difference between the air cavity and the liquid cavity can push the piston to move in a self-adaptive mode, then the change amplitude of the hydraulic pressure is reduced, the resistance borne by the telescopic pipe is reduced, and rigid collision is reduced.

Description

Technical Field

[0001] This utility model relates to a wax injection machine, and more particularly to a wax injection head for the wax injection machine. Background Technology

[0002] Precision casting processes generally include wax injection, welding, slurry application, sanding, drying, dewaxing, sintering, and casting. The wax injection process involves injecting molten wax into a mold made to the shape and size of the product, where it solidifies to form a wax part. This process requires a wax injection machine, whose wax injection head is the component that dispenses the wax and engages with the mold. It typically has a vertical lifting function. In existing technology, the wax injection head of a wax injection machine generally cannot retract, which can easily cause rigid collisions when the nozzle contacts the mold, leading to damage to the wax injection head tube. This is especially problematic when changing molds or adjusting the descent height of the wax injection head due to changes in mold dimensions.

[0003] To address this, a utility model patent (CN219484112U) entitled "A Wax Injection Mechanism for a Wax Injection Machine" has been disclosed. It includes a reducing pipe, a first connecting pipe, a second connecting pipe, and a wax injection pipe. The lower surface of the wax injection pipe has an insertion groove, and an insertion frame is embedded inside the groove. A resistance wire heating element is embedded in the outer surface of the insertion frame. A threaded ring is threaded onto the outer surface of the wax injection pipe, and a spring is nested within it. When the wax injection pipe is impacted, the spring automatically compresses to allow part of the wax injection pipe to extend into the reducing pipe, preventing damage. This design also combines the extension and retraction of the wax injection pipe with its discharge, facilitating automatic feeding. However, because the liquid wax pressure on the upper side of the wax injection pipe increases instantaneously during upward compression, the resistance during retraction surges, potentially causing damage to the wax injection pipe. Summary of the Invention

[0004] This invention provides a wax injection head for a wax injection machine, which solves the problem in the prior art where the wax injection head is easily damaged due to rigid contact when the wax injection machine docks with the mold.

[0005] The above-mentioned technical problems of this utility model are mainly solved by the following technical solution: A wax injection head for a wax injection machine includes a first sleeve and a second sleeve connected end to end. The inner diameter of the second sleeve is smaller than the inner diameter of the first sleeve. A trapezoidal annular washer is provided at the inner end of the first sleeve. A telescopic tube is sleeved inside the second sleeve. A plug is provided inside the first sleeve and fixedly connected to the telescopic tube. The size of the plug is smaller than the inner diameter of the first sleeve. The plug can seal against the trapezoidal annular washer. An injection cavity is formed inside the telescopic tube. A through hole is provided at one end of the telescopic tube near the plug. The other end of the telescopic tube is partially extended out of the second sleeve. A docking part is provided at the head of the telescopic tube. A return spring is provided on the outer side of the telescopic tube between the docking part and the second sleeve. A flow channel communicating with its inner cavity is provided on the first sleeve. A buffer bladder is connected to the flow channel. A piston is provided inside the buffer bladder. The piston divides the inner cavity of the buffer bladder into a gas cavity and a liquid cavity.

[0006] The first sleeve of this invention is fixedly connected to the lifting module on the wax injection machine and is connected to the wax delivery pipeline. The wax injection principle of this invention is as follows: the wax injection head descends synchronously with the lifting module on the wax injection machine, and the docking part gradually approaches the wax injection hole on the mold until they abut against each other. At this time, the telescopic tube is resisted and moves upward relative to the first sleeve. At this time, the hydraulic pressure in the first sleeve increases, and the wax can flow into the buffer tank from the diversion channel. The piston shifts to the air chamber side to avoid a sharp increase in hydraulic pressure. In this way, the resistance encountered by the telescopic tube during the upward movement is small, and the tube body is not easily damaged. After the plug separates from the trapezoidal annular washer, the wax will flow downward through the gap between the plug and the first sleeve and flow into the telescopic tube through the through hole, and finally flow out from the docking part. At this time, the pressure of the wax is completely restored, and the air chamber can push the piston to reset. When the lifting module of the wax machine moves upward, the reset spring can push the telescopic tube to reset, realizing automatic closure and preventing the wax from leaking out.

[0007] Furthermore, the second sleeve is divided into a first section and a second section, which are screwed together and fixed. The first section has a clearance fit with the telescopic tube, while the second section has a guide fit with the telescopic tube. The first section is connected to the first sleeve, and several first sealing rings are fitted on the inner wall of the first section. This design of the second sleeve can provide a good sealing effect while ensuring sufficient guiding effect for the telescopic tube, preventing wax from seeping out from the gap between the second sleeve and the telescopic tube. Moreover, dividing the second sleeve into two sections reduces production and assembly difficulty.

[0008] Furthermore, the second section is equipped with a heating mantle, to which a spiral wire is connected for power supply. The heating mantle can heat the wax liquid inside the telescopic tube in real time, preventing the wax liquid temperature from becoming too low.

[0009] Therefore, this utility model has the following characteristics compared with the prior art: 1. By adding a buffer bladder to the first sleeve, when the hydraulic pressure of the wax changes, the pressure difference between the air chamber and the liquid chamber can be used to push the piston to move adaptively by utilizing the compressible property of the air in the air chamber, thereby reducing the amplitude of hydraulic pressure change, thereby reducing the resistance of the telescopic tube and reducing rigid collision. Attached Figure Description

[0010] Appendix Figure 1 This is a schematic diagram of the telescopic tube of this utility model when it is not under pressure;

[0011] Appendix Figure 2 This is a schematic diagram of the telescopic tube of this utility model under pressure.

[0012] Appendix Figure 3 It is attached Figure 2 Enlarged view of part A. Detailed Implementation

[0013] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0014] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0015] Example 1: See Figure 1 , Figure 2 and Figure 3A wax injection head for a wax injection machine includes a first sleeve 100 and a second sleeve 200 connected end-to-end. The inner diameter of the second sleeve is smaller than that of the first sleeve. A trapezoidal annular washer 110 is provided at the inner end of the first sleeve. A telescopic tube 300 is sleeved inside the second sleeve. A plug 310, which is fixedly connected to the telescopic tube, is provided inside the first sleeve. The size of the plug is smaller than the inner diameter of the first sleeve. The plug can seal against the trapezoidal annular washer. An injection cavity 320 is formed inside the telescopic tube. A section of the telescopic tube near the plug... One end is provided with a through hole 330 that runs through the inside and outside. The other end of the telescopic tube is partially extended out of the second sleeve. The head of the telescopic tube is provided with a docking part 340. A return spring 400 is provided on the outside of the telescopic tube and between the docking part and the second sleeve. The first sleeve is provided with a diversion channel 120 that communicates with its inner cavity. A buffer bladder 500 is connected to the diversion channel. A piston 510 is provided inside the buffer bladder. The piston is provided with two to three sealing rubber rings 511. The piston divides the inner cavity of the buffer bladder into an air chamber 501 and a liquid chamber 502.

[0016] In this embodiment, the first sleeve is fixedly connected to the lifting module on the wax injection machine and is connected to the wax delivery pipeline. The wax injection principle of this embodiment is as follows: the wax injection head descends synchronously with the lifting module on the wax injection machine, and the docking part gradually approaches the wax injection hole on the mold until they abut against each other. At this time, the telescopic tube is resisted and moves upward relative to the first sleeve. At this time, the hydraulic pressure in the first sleeve increases, and the wax can flow into the buffer tank from the diversion channel. The piston shifts to the air chamber side to avoid a sharp increase in hydraulic pressure. In this way, the resistance encountered by the telescopic tube during the upward movement is small, and the tube body is not easily damaged. After the plug separates from the trapezoidal annular washer, the wax will flow downward through the gap between the plug and the first sleeve and flow into the telescopic tube through the through hole, and finally flow out from the docking part. At this time, the pressure of the wax is completely restored, and the air chamber can push the piston to reset. When the lifting module of the wax machine moves upward, the reset spring can push the telescopic tube to reset, realizing automatic closure and preventing the wax from leaking out.

[0017] See Figure 1 The second sleeve is divided into a first section 210 and a second section 220, which are screwed together and fixed. The first section has a clearance fit with the telescopic tube, while the second section has a guide fit with the telescopic tube. The first section is connected to the first sleeve, and several first sealing rings 211 are fitted on the inner wall of the first section. This design of the second sleeve can provide a good seal while ensuring sufficient guidance for the telescopic tube, preventing wax from seeping out from the gap between the second sleeve and the telescopic tube. Moreover, dividing the second sleeve into two sections reduces the difficulty of production and assembly.

[0018] See Figure 1 The second section is equipped with an electric heating mantle 221, to which a spiral wire 222 is connected for connection to a power source. The electric heating mantle can heat the wax liquid inside the telescopic tube in real time, preventing the wax liquid temperature from becoming too low.

[0019] See Figure 1 and Figure 3 The buffer liner includes a liner body 520, a liner cap 530, and a screw connector 540. The screw connector is screwed to the diversion channel, the liner body is screwed to the liner cap, and a second sealing ring 550 is provided between the two.

[0020] See Figure 1 The outer end of the first sleeve is provided with a butt joint 130 and a flange body 140. The butt joint is used to connect with the docking part of the wax injection machine and has a positioning effect. The flange body is used for connection and fixation.

[0021] This invention can be modified in many ways, as will be apparent to those skilled in the art, and such modifications are not considered to depart from the scope of this invention. All such modifications that are obvious to those skilled in the art are included within the scope of these claims.

Claims

1. A wax injection head for a wax injection machine, characterized in that: The system includes a first sleeve and a second sleeve connected end-to-end. The inner diameter of the second sleeve is smaller than that of the first sleeve. A trapezoidal annular washer is provided at the inner end of the first sleeve. A telescopic tube is fitted inside the second sleeve. A plug is provided inside the first sleeve and fixedly connected to the telescopic tube. The size of the plug is smaller than the inner diameter of the first sleeve. The plug can seal against the trapezoidal annular washer. An injection cavity is formed inside the telescopic tube. A through hole is provided on one end of the telescopic tube near the plug. The other end of the telescopic tube extends out of the second sleeve. A docking part is provided at the head of the telescopic tube. A return spring is provided on the outer side of the telescopic tube between the docking part and the second sleeve. A flow channel communicating with its inner cavity is provided on the first sleeve. A buffer bladder is connected to the flow channel. A piston is provided inside the buffer bladder. The piston divides the inner cavity of the buffer bladder into a gas cavity and a liquid cavity.

2. The wax injection head of the wax injection machine according to claim 1, characterized in that: The second sleeve is divided into a first section and a second section, which are screwed together and fixed. The first section and the telescopic tube are in clearance fit, and the second section and the telescopic tube are in guide fit. The first section is connected to the first sleeve, and a plurality of first sealing rings are fitted on the inner wall of the first section.

3. The wax injection head of the wax injection machine according to claim 2, characterized in that: The second section is equipped with an electric heating mantle.

4. The wax injection head of the wax injection machine according to claim 1, characterized in that: The buffer liner includes a liner body, a liner cap, and a screw connector. The screw connector is screwed into the diversion channel, and the liner body is screwed into the liner cap, with a second sealing ring placed between them.

5. The wax injection head of the wax injection machine according to claim 1, characterized in that: The outer end of the first sleeve is equipped with a butt joint and a flange body.

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