Casting molds

Abstract

To provide a casting die which can improve maintainability than before.SOLUTION: Provided is a casting die which presses a cast body formed inside a cavity with a push pin in a state of being die-opened to separate the same from a stationary die or a movable die and comprises: an auxiliary cavity which is communicated with the cavity and forms an auxiliary molded body; and an auxiliary push pin which presses the auxiliary molded body from a direction same as that of the push pin, in which the auxiliary push pin comes into contact with the cast body before the push pin does.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a casting mold.

Background Art

[0002] Patent Document 1 below discloses a mold capable of easily adjusting the overflow amount when manufacturing a cast product. This mold includes a fixed mold member, a movable mold member that forms a space corresponding to the product shape between the fixed mold member, a chill vent provided with a second block that forms a gas vent path between the first block and the first block, and a first block. The tip is exposed to the gas vent path and is provided so as to be able to advance and retreat in the gas vent path, and includes a first extrusion pin or the like that separates the cast product from the movable mold member by pressing the cast product at the tip.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the prior art, since the auxiliary extrusion pin arranged via the protruding mechanism at the tip of the first extrusion pin directly presses the part of the cast product formed in the gas vent path, after the tip of the auxiliary extension extrusion pin wears or deform, the process (maintenance) of replacing the auxiliary extension extrusion pin becomes difficult. That is, there is a problem that the productivity decreases due to the poor maintainability of the extrusion pin.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a casting mold capable of improving the maintainability more than before.

Means for Solving the Problems

[0006] To achieve the above objective, the present invention employs a casting mold as a solution relating to a casting mold, wherein a casting body formed in the cavity is separated from a fixed mold or a movable mold by pressing it with a push pin while the mold is open, and the mold comprises an auxiliary cavity that communicates with the cavity and forms an auxiliary molded body extending in the direction of movement of the movable mold, and an auxiliary push pin that presses the auxiliary molded body from the same direction as the push pin. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a casting mold that can improve maintainability compared to conventional molds. [Brief explanation of the drawing]

[0008] [Figure 1] These are a top view (a) and a front view (b) showing an overview of a casting mold A according to one embodiment of the present invention. [Figure 2] This is a perspective view showing the structure of a semi-finished casting B according to one embodiment of the present invention. [Figure 3] This is a schematic diagram illustrating the operation and effect of a casting mold A according to one embodiment of the present invention. [Modes for carrying out the invention]

[0009] One embodiment of the present invention will be described below with reference to the drawings. The casting mold A according to this embodiment is a manufacturing apparatus for semi-finished castings in which multiple product castings are integrally connected. The product castings are, for example, throttle body housings. As is well known, a throttle body is a butterfly valve that adjusts the flow rate (amount of air intake) of air taken into an engine, and comprises a housing (throttle body housing) made of a predetermined metal (for example, aluminum). The casting mold A according to this embodiment is used to manufacture such semi-finished castings.

[0010] As shown in Figure 1, this casting mold A comprises at least a fixed mold A1, a movable mold A2, a plurality of first push pins F1, and a plurality of second push pins F2. By clamping the fixed mold A1 and the movable mold A2 together, the casting mold A forms a cavity C (molding space) inside that corresponds to the shape of the semi-finished casting.

[0011] As shown in the figure, this cavity C comprises a gate cavity c1, a runner cavity c2, a pair of connecting cavities c3a and c3b, a pair of main body cavities c4a and c4b, a pair of vent cavities c5a and c5b, and five columnar molded body cavities c6a to c6e.

[0012] These gate cavity c1, runner cavity c2, pair of connecting cavity c3a, c3b, pair of main body cavity c4a, c4b, pair of venting cavity c5a, c5b, and five columnar molded cavity c6a to c6e are all in communication as a whole.

[0013] Such a casting mold B is provided with an injection port D at one end through which molten metal flows and faces a cavity C. The molten metal is supplied from the injection port D to the cavity C, fills the cavity C, and then cools to become a semi-finished casting B.

[0014] Furthermore, this casting mold A is provided with a pair of gas vents Ea and Eb. These gas vents Ea and Eb are exhaust ports that discharge air and other gases from inside the cavity C to the outside when molten metal is poured into the cavity C.

[0015] In casting mold A, a cavity C is formed by the contact between the fixed mold A1 and the movable mold A2. Molten metal is poured into the cavity C and cooled to form a semi-finished casting B. Then, in this casting mold A, the semi-finished casting B is removed by separating the fixed mold A1 and the movable mold A2.

[0016] As shown in Figure 2, the semi-finished casting B produced in the casting mold A comprises a columnar gate portion 1, a runner portion 2, a pair of connecting portions 3a, 3b, a pair of main body portions 4a, 4b, a pair of venting portions 5a, 5b, and a pair of columnar molded bodies 6a to 6e. The semi-finished casting B, which is a single piece of these parts, is based on the shape of the cavity C in the casting mold A and is substantially the same shape as the cavity C.

[0017] In other words, of the cavities C of the casting mold A, the gate cavity c1 is the internal space for forming the columnar gate portion 1, and the runner cavity c2 is the internal space for forming the runner portion 2. Also, of the pair of connecting cavities c3a and c3b, one connecting cavity c3a is the internal space for forming one connecting portion 3a, and the other connecting cavity c3b is the internal space for forming the other connecting portion 3b.

[0018] Furthermore, of the pair of main body cavities c4a and c4b, one main body cavity c4a is the internal space for forming one of the connecting parts 3a, and the other main body cavity c4b is the internal space for forming the other connecting part 3b. Also, of the pair of vent cavities c5a and c5b, one vent cavity c5a is the internal space for forming one of the vent parts 5a, and the other vent cavity c5b is the internal space for forming the other vent part 5b.

[0019] Furthermore, of the five columnar molded body cavities c6a to 6e, the first columnar molded body cavity c6a is the internal space for forming the first columnar molded body 6a, the second columnar molded body cavity c6b is the internal space for forming the second columnar molded body 6b, the third columnar molded body cavity c6c is the internal space for forming the third columnar molded body 6c, the fourth columnar molded body cavity c6d is the internal space for forming the fourth columnar molded body 6d, and the fifth columnar molded body cavity c6e is the internal space for forming the fifth columnar molded body 6e.

[0020] The plurality of first push pins F1 and second push pins F2 are movable pins that press the semi-finished product casting B from the side of the movable mold A2 when the casting mold A is opened, and they have the same length. That is, the plurality of first push pins F1 and second push pins F2 separate the semi-finished product casting B from the movable mold A2 by advancing toward the semi-finished product casting B and pressing the semi-finished product casting B from the side.

[0021] Such a plurality of first push pins F1 and second push pins F2 are provided so as to be retractable with respect to the cavity C as shown in the figure. That is, the plurality of first push pins F1 and second push pins F2 are rod-shaped members embedded in the movable mold A2 so as to face the cavity C, and the central axis direction is set to the direction facing the cavity C.

[0022] Among the plurality (seven) of first push pins F1 and second push pins F2, two first push pins F1 are normal push pins provided on the movable mold A2 so as to face a pair of main body part cavities c4a and c4b. Five second push pins F2 are 5 auxiliary push pins provided on the movable mold A2 so as to face the columnar molded body cavities c6a to c6e. As shown by the auxiliary line L in Fig. 1(a), the contact position of the second push pin F2 is at least the same as the contact position of the first push pin F1.

[0023] In the semi-finished product casting B of the present embodiment, the columnar gate portion 1 is a portion having a substantially columnar shape. This columnar gate portion 1 is a portion formed by injecting molten metal from the injection port D on one end side in the central axis direction (the back side in Fig. 2). One end of the runner portion 2 is connected to the other end side in the central axis direction of such a columnar gate portion 1. That is, the molten metal injected from the injection port D to one end side of the gate portion cavity c1 flows from the other end side of the gate portion cavity c1 into one end portion of the runner portion cavity c2.

[0024] The runner portion 2 is a substantially flat plate-shaped part that extends in a direction perpendicular to the central axis of the columnar gate portion 1. That is, this runner portion 2 has a pair of main surfaces perpendicular to the central axis of the columnar gate portion 1. One end of this runner portion 2 (the lower end in Figure 2) is connected to the other end of the columnar gate portion 1, and the other end (the upper end in Figure 2) is connected to one end of each of the pair of connecting portions 3a and 3b.

[0025] The pair of connecting parts 3a and 3b are the parts that connect the pair of main body parts 4a and 4b to the runner part 2. The pair of connecting parts 3a and 3b linearly connect the pair of main body parts 4a and 4b, and the intermediate part connects to the other end of the runner part 2 (the upper end in Figure 2).

[0026] Here, the runner portion 2 and the pair of connecting portions 3a and 3b extend parallel to a plane perpendicular to the central axis direction of the columnar gate portion 1. That is, the pair of main body portions 4a and 4b are interconnected by the runner portion 2 and the pair of connecting portions 3a and 3b having such extending directions.

[0027] The pair of main body parts 4a and 4b form the housing of the throttle valve. More precisely, the pair of main body parts 4a and 4b do not form the entire housing of the throttle valve, but rather form a major (partial) part of it.

[0028] Of the pair of main body sections 4a and 4b, one main body section 4a is equipped with a cylindrical section that connects to the vehicle's air intake pipe (cylindrical pipe). The direction of the central axis of this cylindrical section is set to be the same as or approximately the same as the central axis of the columnar gate section 1. That is, the central axis direction of the cylindrical section in one of the main body sections 4a is perpendicular to the direction in which the runner section 2 and the pair of connecting sections 3a and 3b described above extend.

[0029] The other main body portion 4b is equipped with a cylindrical portion that connects to the vehicle's air intake pipe (cylindrical pipe). The direction of the central axis of this cylindrical portion is set to be the same as or approximately the same as the central axis of the columnar gate portion 1. That is, the cylindrical portion in the other main body portion 4b has its central axis direction perpendicular to the direction in which the runner portion 2 and the pair of connecting portions 3a and 3b extend, just like the cylindrical portion in the first main body portion 4a.

[0030] The pair of gas vents 5a and 5b are thin-walled portions formed between the pair of main body portions 4a and 4b and the pair of gas vents Ea and Eb. Specifically, of the pair of gas vents 5a and 5b, one gas vent 5a is a thin-walled portion formed between one main body portion 4a and one gas vent Ea. The other gas vent 5b is a thin-walled portion formed between the other main body portion 4b and the other gas vent Eb.

[0031] The five columnar molded bodies 6a to 6e are columnar portions provided in the middle of a pair of gas venting sections 5a and 5b, in the middle of a pair of connecting sections 3a and 3b, and in the middle of the runner section 2. Specifically, of the five columnar molded bodies 6a to 6e, the first columnar molded body 6a is a columnar portion provided in the middle of one of the gas venting sections 5a, and the second columnar molded body 6b is a columnar portion provided in the middle of the other gas venting section 5b.

[0032] Furthermore, the third columnar molded body 6c is a columnar portion provided in the middle of one connecting portion 3a, and the fourth columnar molded body 6d is a columnar portion provided in the middle of the other connecting portion 3a. In addition, the fifth columnar molded body 6e is a columnar portion provided in the middle of the runner portion 2. The central axis direction of these five columnar molded bodies 6a to 6e is set to be parallel to the opposing direction of the fixed mold A1 and the movable mold A2, that is, to the direction of advancement and retraction of the multiple push pins F1 and F2.

[0033] Next, a method for manufacturing a semi-finished casting B using the casting mold A according to this embodiment will be described with reference to Figure 3.

[0034] In the method for manufacturing a semi-finished casting B using a casting mold A, a cavity C (molding space) corresponding to the shape of the semi-finished casting B is first formed inside by aligning a fixed mold A1 and a movable mold A2. Then, in this manufacturing method, molten metal is injected into the cavity C from the injection port D of the casting mold A, thereby filling the cavity C with molten metal.

[0035] In this manufacturing method, the molten metal in the cavity C is cooled by cooling the casting mold A, thereby solidifying the molten metal and forming a semi-finished casting B. Then, the casting mold A is opened, and the semi-finished casting B is pressed with a plurality of first push pins F1 and second push pins F2 to separate the semi-finished casting B from the movable mold A2 (casting mold A). The semi-finished casting B thus cast is inspected for shape, defects, etc., and the manufacturing is completed.

[0036] In conventional methods of separating castings from molds, push pins are used to press the casting. However, the length of the part that comes into contact with and is pressurized by the push pin varies depending on whether it is the gate or a semi-finished casting. A longer push pin pressurizing the gate makes it more susceptible to deformation due to the bending stress caused by the pressure. Consequently, conventional castings with longer push pins pressurizing the gate have a shorter lifespan for the push pins and poor maintainability of the push pins, resulting in reduced productivity.

[0037] In contrast, in this embodiment, when separating the semi-finished casting B from the movable mold A2, the casting mold A applies a pressing force to the semi-finished casting B using a first push pin F1 (normal push pin) that pushes the semi-finished casting B and a second push pin F2 (auxiliary push pin) that pushes an auxiliary molded body provided at the gate, as shown by the arrows in Figure 3.

[0038] In this process, the second push pin F2 (auxiliary push pin) contacts the product casting B at the same time as the first push pin F1 (normal push pin), applying a pressing force. Therefore, it becomes easy to adjust the lengths of the first push pin F1 (normal push pin) and the second push pin F2 (auxiliary push pin). By shortening the second push pin F2 (auxiliary push pin), the difference in bending stress between it and the first push pin F1 (push pin) is reduced, eliminating the difference in lifespan between the first push pin F1 (normal push pin) and the second push pin F2 (auxiliary push pin). This extends the lifespan of the second push pin F2 (auxiliary push pin), reducing the frequency of maintenance and improving productivity.

[0039] Also, 5 The second push pin F2 is 2 Although the wear is more severe than that of the first push pin F1, the first push pin F1 and the second push pin F2 are set to the same length, and the position of the second exposed surface of multiple first push pins F1 and second push pins F2 in the forward and backward direction is set to be further back than the first exposed surface, so there is a margin of safety against wear. 2 It is larger than the first push pin F1.

[0040] In other words, according to this embodiment, it is possible to extend the lifespan of the first push pin F1 that separates the semi-finished casting B (casting) from the casting mold A (mold) compared to conventional methods. Furthermore, according to this embodiment, 5 Although the second push pin F2 wears more than the first push pin F1, a sufficient margin of safety against wear can be ensured. Therefore, according to this embodiment, it is possible to provide a method for manufacturing a casting mold A and a semi-finished casting B that can improve maintainability compared to conventional methods.

[0041] Furthermore, according to this embodiment, columnar molded body cavities c6a and c6b (auxiliary cavities) are provided in the gas vent cavities c5a and c5b that discharge gas from inside cavity C to the outside, and the columnar molded bodies 6a and 6b (auxiliary molded bodies) formed in the columnar molded body cavities c6a and c6b are pushed by the second push pin F2 (auxiliary push pin), so that when removing the semi-finished casting body B from the casting mold A, it is possible to remove it smoothly without tilting.

[0042] The present invention is not limited to the embodiments described above, and for example, the following modifications are possible. (1) In the above embodiment, the case in which the present invention is applied to a semi-finished casting A relating to a throttle body has been described, but the present invention is not limited thereto. That is, the pair of main body parts 4a and 4b in the above embodiment are not limited to the housing of a throttle valve, but may be all or part of various components.

[0043] (2) In the above embodiment, the semi-finished casting A was described with a pair of main body parts 4a and 4b, but the present invention is not limited thereto. That is, the number of main body parts is not limited to two (a pair), but may be one or three or more.

[0044] (3) In the above embodiment, 5 Although a first push pin F1 and two second push pins F2 are provided, the present invention is not limited to this. The number and position of the first push pin F1 (normal push pin) and the second push pins F2 (auxiliary push pins) should be appropriately set according to the size and shape of the casting.

[0045] (4) In the above embodiment, the first push pin F1 (normal push pin) and the second push pin F2 (auxiliary push pin) were set to the same length, but the present invention is not limited thereto. Maintainability may be further improved by making the second push pin F2 (auxiliary push pin), which is prone to wear, longer than the first push pin F1 (normal push pin).

[0046] (Note 1) A casting mold for separating a casting formed in a cavity from a fixed or movable mold by pressing it with a push pin while the mold is open, comprising: an auxiliary cavity that communicates with the cavity and forms an auxiliary molded body extending in the direction of movement of the movable mold; and an auxiliary push pin that presses the auxiliary molded body from the same direction as the push pin.

[0047] (Note 2) The casting mold according to Appendix 1, wherein the contact position between the auxiliary push pin and the auxiliary molded body is at least the same as the contact position between the casting body and the push pin in the direction of movement of the push pin and the auxiliary push pin.

[0048] (Note 3) The casting mold described in Appendix 1 or 2, wherein the auxiliary cavity is provided in a venting cavity for discharging gas from within the cavity. [Explanation of Symbols]

[0049] A casting mold A1 Fixed mold A2 Movable mold B. Semi-finished casting C Cavity C c1 Gate cavity c2 Runner section cavity c3a, c3b connecting cavity c4a, c4b Main body cavity c5a, c5b venting cavity c6a~c6e Columnar molded body cavity (auxiliary cavity) D Injection port Ea, Eb gas vents 1. Columnar gate section 2 Runners 3a, 3b connection part 4a, 4b1 Main body 5a, 5b Gas vent section 6a~6e Columnar molded body (auxiliary molded body)

Claims

1. A casting mold that separates a casting formed in a cavity from a fixed or movable mold by pressing it with a push pin while the mold is open, An auxiliary cavity that communicates with the cavity and forms an auxiliary molded body extending in the direction of movement of the movable mold, The system includes an auxiliary push pin that presses the auxiliary molded body from the same direction as the aforementioned push pin, A casting mold in which the push pin and the auxiliary push pin have the same length, the contact position with the object to be pressed in the direction of travel of the push pin and the auxiliary push pin is the same, and the push pin and the auxiliary push pin are in a positional relationship such that they contact the casting at the same time.

2. The casting mold according to claim 1, wherein the auxiliary cavity is provided in a venting cavity for discharging gas from within the cavity.

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