Variable cross-section liquid injection mechanism

Abstract

The invention discloses a variable cross-section liquid injection mechanism which comprises an injection charging barrel and a telescopic punch, the injection charging barrel is provided with a variable cross-section injection cavity, the telescopic punch is in sliding fit with the injection cavity and reciprocates in the injection cavity, the telescopic punch is provided with a punch surface in contact with a liquid material in the injection cavity, the cross-section size of the punch surface is variable, and the cross-section size of the punch surface is variable. And when the telescopic puncher pin reciprocates, the peripheral edge of the puncher pin surface is always in close contact with the inner wall of the injection cavity, and injection is formed on the liquid. The variable-cross-section injection cavity is matched with the telescopic punch to achieve the purpose of variable-cross-section injection, the relation among injection pressure, injection quantity, injection speed, mold cavity filling time and pressure maintaining intensity is changed by optimizing the shape of the injection charging barrel, the product quality and the qualified rate are improved, the die casting process is optimized, the product quality is improved, and the production cost is reduced. And a new adjusting scheme is provided for the injection process.

Description

Technical Field

[0001] The present invention belongs to the technical field of die casting, and more specifically, relates to a variable cross-section liquid injection mechanism. Background Art

[0002] Die casting means that the injection mechanism of a die casting machine uses high pressure to push an injection piston, and quickly fills the liquid object in the injection barrel into the mold cavity. A traditional injection barrel refers to an annular cylinder for containing molten liquid, and its cross-sectional size remains unchanged. During die casting, according to production requirements, it is necessary to adjust injection pressure, injection volume, etc. to adjust die casting parameters and control the quality of die casting products. The current adjustment method is to change the driving pressure and speed, and thus achieve the adjustment of injection parameters. This adjustment method is achieved by adjusting the prime mover, and has relatively high requirements for the pressure change of the power system, and the cost is correspondingly high. Therefore, we design a variable cross-section liquid injection mechanism that can also achieve the adjustment of injection parameters when the pressure supply of the power system remains unchanged. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a variable cross-section liquid injection mechanism. To solve the above technical problem, the basic concept of the technical solution adopted by the present invention is: A variable cross-section liquid injection mechanism includes an injection barrel and a telescopic punch. The injection barrel is provided with an injection cavity with a variable cross-section. The telescopic punch is slidably matched with the injection cavity and reciprocates in the injection cavity. The telescopic punch is provided with a punch surface that contacts the liquid material in the injection cavity. The cross-sectional size of the punch surface is variable, and when the telescopic punch reciprocates, the peripheral edge of the punch surface always closely contacts the inner wall of the injection cavity and forms an injection on the liquid.

[0004] Further, the cross-sectional area of the injection cavity changes in a functional manner from one end to the other end.

[0005] Further, the cross-sectional area of the injection cavity changes in a linear function manner from one end to the other end.

[0006] Further, the injection cavity includes at least two connecting segments with different slopes, and the connecting segments are straight line segments or arc segments.

[0007] Further, the cross-sectional area of the injection cavity near the gate end is larger than the cross-sectional area of the other end.

[0008] Further, the cross-sectional area of the injection cavity near the gate end is smaller than the cross-sectional area of the other end.

[0009] Further, the injection cavity is trapezoid-shaped and has an inclined surface. The telescopic punch includes a piston rod, a base, and a slider. One end of the piston rod is connected to the base, and the other end is connected to the driving mechanism. The slider is slidably connected to the inclined surface and the two side surfaces of the injection cavity. The base is slidably connected to the slider. A spring is installed on the slider. One end of the spring is fixedly connected to the slider, and the other end is connected to the base. The spring is in a compressed state, and its elastic force pushes the slider away from the base to maintain its close contact state with the inclined surface of the injection cavity. The punch surface is formed by the base and the slider, and when the base and the slider slide relative to each other, the contact area between the punch surface and the liquid in the injection cavity changes.

[0010] Further, a guiding groove is provided on the base, and the slider is provided with a guiding protrusion matching the guiding groove. The guiding protrusion is in limit sliding connection with the guiding groove.

[0011] Further, an arc edge is provided on the bottom surface of the slider. The slider is slidably connected to the inner wall of the injection cavity through the arc edge. The cross-section of the arc edge is in the shape of an arc protrusion, and the vertex of the arc is in line contact with the inner wall of the injection cavity.

[0012] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art.

[0013] The present invention uses a variable-section injection cavity in cooperation with a telescopic punch to achieve the purpose of variable-section injection, realizes optimizing the relationship between injection pressure, injection volume, injection speed, mold filling cavity time, and holding pressure by optimizing the shape of the injection barrel, so as to improve product quality and qualification rate, further optimize the die-casting process and improve product quality, and provides a new adjustment parameter scheme for the injection process.

[0014] The following further describes in detail the specific embodiments of the present invention with reference to the accompanying drawings. Description of the Drawings

[0015] The accompanying drawings, as part of this application, are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention, but do not constitute an improper limitation to the present invention. Obviously, the accompanying drawings in the following description are only some embodiments, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts. In the drawings: Figure 1 is a schematic diagram for comparative analysis of variable cross-section and constant cross-section of the present invention; Figure 2 is an example schematic diagram of the variable-section injection cavity of the present invention; Figure 3 is a schematic diagram of the structure of Embodiment 1 of the present invention; Figure 4 is a schematic diagram of the change of the telescopic punch in Embodiment 1 of the present invention; Figure 5 Schematic diagram of the guiding groove and guiding projection in the first embodiment of the present invention; Figure 6 Schematic diagram of the structure in the second embodiment of the present invention; Figure 7 is Figure 6 Enlarged view of part A in Figure 8 Right view of the structure in the second embodiment of the present invention; Figure 9 Schematic diagram of the guiding groove and guiding projection in the second embodiment of the present invention.

[0016] In the figure: 1 - injection barrel; 11 - injection cavity; 201 - piston rod; 202 - base; 203 - slider; 204 - spring; 2031 - arc edge.

[0017] It should be noted that these drawings and text descriptions are not intended to limit the scope of the concept of the present invention in any way, but to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Specific embodiments

[0018] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0019] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0020] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] A variable cross-section liquid injection mechanism according to the present invention includes an injection barrel 1 and a telescopic punch. Among them, the injection barrel 1 is provided with an injection cavity 11 with a variable cross-section. The injection cavity 11 is used to contain liquid materials such as molten metal or non-metallic solution. The telescopic punch is slidably engaged with the injection cavity 11 and reciprocates within the injection cavity 11 to form an injection mechanism. The telescopic punch is provided with a punch surface in contact with the solution in the injection cavity 11. The cross-sectional size of the punch surface is variable. Moreover, when the telescopic punch reciprocates, the cross-sectional area of the punch surface changes with the change of the cross-section of the injection cavity 11. The peripheral edge of the punch surface is always in close contact with the inner wall of the injection cavity 11 and presses the liquid in the cavity to form injection. The variable cross-sectional size means that the geometric dimensions (such as length, width, height) of the cross-section can change. The change of the size directly affects the geometric characteristics of the contact surface, and the change of the area is the result of the change of the size. Since the pressurization process of the punch surface is a continuous gradual change process, the gradual change of the geometric dimensions just fits this gradual change process, that is, the change of the size causes the change of the area, so that the area of the liquid pressure surface changes. Here, the punch surface is a defined contact surface. When the punch moves, since the cross-section of the injection cavity 11 will change, in order to ensure the injection sealability, the punch surface also needs to change accordingly, so as to ensure the sealed injection.

[0022] Combined with the attached Figure 1 shown ([ Figure 1 The shape of the injection cavity 11 shown in (a) is only an example. Figure 1 (b) shows the existing traditional equal cross-section injection cavity), let the opening area of one end of the injection barrel 1 close to the mold gate (the left port in the figure) be A1, and the opening area of the other end be A2. The area of one end of the telescopic punch 2 (the mark in the figure is only to show this part, not representing the specific structure) close to the mold gate is B1, which is the pressure application area to the solution in the cavity, and the opening area of the other end is B2, representing the actual force-receiving area for receiving the system injection force. When B1 moves along the length direction of the injection barrel 1, it changes according to the shape of the inner wall of the barrel: if A1 < A2, the injection cavity is convergent; if A1 > A2, the injection cavity is divergent; if A1 = A2, it degenerates into a traditional equal cross-section barrel. Usually, B1 < B2, that is, the punch amplifies the system injection pressure and applies it to the solution in the mold cavity to play a role in boosting pressure and holding pressure.

[0023] Compared with the traditional equal cross-section barrel, the variable cross-section injection barrel has the following advantages: 1. Let the opening area of the equal cross-section barrel be A0. If A2 > A1 = A0, under the condition of injecting the same volume (or weight) of solution, the variable cross-section injection barrel shortens the moving stroke of the punch and at the same time shortens the length of the barrel. In other words, keeping the initial speed of the punch, the injection time can be reduced. If the same barrel length is maintained (i.e., L1 = L2), the volume (mass) of the injection liquid can be increased; 2. It can achieve the effect of injection boosting. If the pressure on the right side of the punch is p, then the pressure on the left side of the punch, that is, the injection pressure, is (B2 / B1)*p. Under the condition of the same injection volume, it can be assumed that B1 < A0, so it further enhances the boosting effect. 3. It provides new adjustment parameters and solutions for the injection process. Because the relationship between injection pressure, injection volume, injection speed, filling time, and holding pressure can be controlled and adjusted by changing the shape of the injection barrel, so as to improve the product quality and qualification rate. 4. Under the condition of the same injection metal volume (mass) or the same injection force, the technical index requirements for the injection power system can be reduced, thereby reducing the manufacturing cost.

[0024] Of course, Figure 1 The injection cavity 11 shown in (a) is only an example. The cross-sectional area change of the injection cavity 11 can be set according to requirements (several cross-sectional change examples are shown in (a), (b), (c), and (d) in the appendix). For example, it changes as a function from one end to the other end, including but not limited to linear functions, power functions, exponential functions, etc., which are not listed here. Different variable cross-section adjustment schemes can be realized. Preferably, a linear function change can be considered. The cross-sectional area of the injection cavity 11 near the gate is larger or smaller than the cross-sectional area of its other end, which is also beneficial for controlling the injection pressure and injection volume according to the linear change. Figure 2 Embodiment 1 As shown in

[0025] For example, Figures 3 to 5 shown, a variable cross-section liquid injection mechanism described in this embodiment includes an injection barrel 1 and a telescopic punch. Among them, the injection barrel 1 is provided with a variable cross-section injection cavity 11. The injection cavity 11 is in the shape of a frustum of a pyramid and has an inclined surface. The telescopic punch reciprocates in the injection cavity 11, and the area of the punch surface in contact with the metal liquid in the injection cavity 11 is variable. When the telescopic punch reciprocates, the peripheral edge of the punch surface is always in close contact with the inner wall of the injection cavity 11 to form an injection on the liquid in the cavity.

[0026] Specifically, the telescopic punch includes a piston rod 201, a base 202, and a slider 203. One end of the piston rod 201 is connected to the base 202, and the other end is connected to a driving mechanism. As shown in the accompanying drawings, the slider 203 is slidably connected to the inclined surface and the two side surfaces of the inclined surface of the injection cavity 11. The base 202 is slidably connected to the slider 203, and their mutual sliding direction is perpendicular to the axis of the injection cavity 11. A spring 204 is installed on the slider 203. One end of the spring 204 is fixedly connected to the slider 203, and the other end is connected to the base 202. The spring 204 is in a compressed state, and its elastic force pushes the slider 203 away from the base 202 to keep it in close contact with the inclined surface of the injection cavity 11. It can be seen that in this example, the punch surface is formed by the base 202 and the slider 203. When the base 202 and the slider 203 slide relative to each other, the contact area between the punch surface and the molten metal in the injection cavity 11 changes. Combined with the attached Figure 4 schematic diagram, when the punch surface has the minimum area, only the left side surface of the slider 203 acts as the punch surface.

[0027] To ensure the stable sliding of the slider 203 and the base 202, a guide groove is provided on the base 202, and a guide protrusion matching the guide groove is provided on the slider 203. The guide protrusion is slidably connected to the guide groove with limited movement, as shown in the attached Figure 5 schematic diagram. Of course, other forms of structures can also be used, as long as they can meet the requirements of ensuring the cooperation, maintaining the seal of the injection cavity 11 when the area of the punch surface changes, and ensuring the stable injection, other mechanical structures disclosed in the prior art can be adopted. Embodiment 2

[0028] Combined with the attached Figures 6 - 9 schematic diagram, the difference between this embodiment and Embodiment 1 is that the inclined surface of the injection cavity 11 includes two straight-segment surfaces with different inclinations. Referring to the attached Figure 6 , the two straight-segment surfaces are defined as M1 and M2 respectively. The inclinations of M1 and M2 are different. In the figure, the inclination of M1 is less than that of M2, which is equivalent to two different injection cross-sections. If the injection force remains unchanged, two different effects can be achieved for the injection volume and the injection speed, which can meet different injection requirements. When the inclination changes and transitions, it is necessary to ensure the sealing between the slider 203 and the inner wall of the injection cavity 11. In this example, an arc edge 2031 is provided on the bottom surface of the slider 203. Combined with the attached Figures 7 - 9 schematic diagram, the arc edge 2031 is in the shape of an arc protrusion, and the vertex of the arc is in line contact with the inner wall of the injection cavity 11. During the inclination transition, the line contact can ensure the sealing during the transition, thereby ensuring the stable injection. The line contact mentioned here can be a straight line, a broken line, or an arc contact, which matches the transition line between M1 and M2 to ensure that the seal can be maintained at the transition. Preferably, the arc edge 2031 in this example is in the shape of a straight strip, that is, perpendicular to the moving direction of the slider 203. Correspondingly, the transition line between M1 and M2 is also perpendicular to the moving direction of the slider 203.

[0029] It should be noted that only different effects of changing the punch face are illustrated here by way of example (changing the straight line segment to an arc segment will also have different effects). The essence of the present invention is to change the shape of the injection cavity 11 to achieve variable cross-section injection, realize the change and control of the solution injection parameters, and further optimize the die-casting process and improve the product quality. As for how the punch shape matches the cross-section of the injection cavity, different forms can be adopted according to the actual design.

[0030] The above are only the preferred embodiments of the present invention and do not impose any formal restrictions on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the technical content prompted above within the scope of the technical solution of the present invention. However, as long as the content does not depart from the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the present invention.

Claims

1. A variable cross-section liquid injection mechanism, characterized in that: Comprising a shot sleeve (1) and a telescopic punch, the shot sleeve (1) is provided with a shot cavity (11) having a variable cross-section, the telescopic punch is slidably engaged with the shot cavity (11) and reciprocates within the shot cavity (11), the telescopic punch is provided with a punch face that contacts the liquid material within the shot cavity (11), the cross-sectional dimension of the punch face is variable, and when the telescopic punch reciprocates, the peripheral edge of the punch face is always in close contact with the inner wall of the shot cavity (11) and forms a shot on the liquid.

2. The variable cross-section liquid injection mechanism according to claim 1, characterized in that: The cross-sectional area of the shot cavity (11) changes as a function from one end to the other end.

3. A variable cross-section liquid injection mechanism according to claim 1, characterized in that: The cross-sectional area of the shot cavity (11) changes linearly as a function from one end to the other end.

4. A variable cross-section liquid injection mechanism according to claim 1, characterized in that: The shot cavity (11) at least includes two connecting segments with different slopes, and the connecting segments are straight line segments or arc segments.

5. The variable cross-section liquid injection mechanism according to claim 3, characterized in that: The cross-sectional area of the shot cavity (11) near the gate end is larger than the cross-sectional area of its other end.

6. The variable cross-section liquid injection mechanism according to claim 3, wherein: The cross-sectional area of the shot cavity (11) near the gate end is smaller than the cross-sectional area of its other end.

7. A variable cross-section liquid injection mechanism according to claim 1, characterized in that: The shot cavity (11) is in the shape of a trapezoid body and has an inclined surface. The telescopic punch includes a piston rod (201), a base (202), and a slider (203). One end of the piston rod (201) is connected to the base (202), and the other end is connected to a driving mechanism. The slider (203) is slidably connected to the inclined surface and the two side surfaces of the inclined surface of the shot cavity (11). The base (202) is slidably connected to the slider (203). A spring (204) is installed on the slider (203). One end of the spring (204) is fixedly connected to the slider (203), and the other end is connected to the base (202). The spring (204) is in a compressed state, and its elastic force pushes the slider (203) away from the base (202) to maintain its close contact state with the inclined surface of the shot cavity (11); The punch face is formed by the base (202) and the slider (203), and when the base (202) and the slider (203) slide relative to each other, the contact area between the punch face and the liquid within the shot cavity (11) changes accordingly.

8. A variable cross-section liquid injection mechanism according to claim 7, characterized in that: A guiding groove is provided on the base (202), and the slider (203) is provided with a guiding protrusion that matches the guiding groove. The guiding protrusion is in a limiting sliding connection with the guiding groove.

9. The variable cross-section liquid injection mechanism according to claim 7, characterized in that: An arc edge (2031) is provided on the bottom surface of the slider (203). The slider (203) is slidably connected to the inner wall of the shot cavity (11) through the arc edge (2031). The cross-section of the arc edge (2031) is in the shape of an arc protrusion, and the vertex of the arc is in line contact with the inner wall of the shot cavity (11).

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