JP2002283003A - Casting method and metallic mold apparatus for casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cast product having small draft of an inner peripheral surface or an outer peripheral surface. SOLUTION: In a movable mold 226 in a metallic mold apparatus for casting, a hollow cylindrical part 280 having the tapered inner peripheral surface 304 is integrally arranged, and in a fixed mold 224, a tapered member 310 having the tapered outer peripheral surface 326 corresponding to the tapered inner peripheral surface 304, is arranged. The outer peripheral surface of the hollow cylindrical part 280 is constituted of a cavity surface 300 for forming the inner peripheral surface of a cylindrical bore 12. The tapered inner peripheral surface 304 and the tapered outer peripheral surface 326 are shrink fitted by closing the molds 224, 226 and the hollow cylindrical part 280 is widened to the diameter at the cavity 236 side with an elastic deformation. Molten metal is poured into the cavity 236 while the hollow cylindrical part 280 is keep in the elastic deformation state After solidifying the molten metal, the molds 224, 226 are opened and the elastic deformation of the hollow cylindrical part 280 is eliminated. A gap in the radius direction is formed between the outer peripheral surface of the hollow cylindrical part 280 and the inner peripheral surface of the cylinder bore 12 and then, a cylinder block 10 can easily be ejected off from the movable mold 226.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for producing
Also, the present invention relates to a method for casting a casting having at least one of an inner peripheral surface and an outer peripheral surface with a small draft angle, and a casting mold apparatus suitable for carrying out the method.

[0002]

2. Description of the Related Art As a method of casting a casting having at least one of an inner peripheral surface and an outer peripheral surface, a slide core is arranged in a cavity inside a mold, and the outer peripheral surface of the slide core defines the cavity. In general, a method of forming a part of a cavity surface, injecting a molten metal into the cavity, and forming an inner peripheral surface of a casting with a slide core is used. After the molten metal in the cavity solidifies, the slide core is separated from the cast product.However, since the molten metal contracts during solidification, clamping force acts on the slide core to separate the slide core from the cast product. Becomes difficult. Therefore, a draft is provided to the slide core to facilitate detachment. However, in many cases, the inner peripheral surface of the cast product formed by the slide core does not necessarily have a gradient. In such a case, the gradient is removed later by machining to form a straight inner peripheral surface. Therefore, in order to make the machining allowance as small as possible, it is desirable to reduce the draft as much as possible, and one method for that is described in JP-A-7-60399. The slide core is made of a material having a thermal expansion coefficient equal to or higher than that of the material of the casting.
By doing so, the slide core is heated to almost the same temperature at the time when the molten metal solidifies and becomes a casting,
After that, the temperature of the slide core decreases as the temperature of the casting decreases. Since the slide core is made of a material having a thermal expansion coefficient equal to or higher than that of the material of the casting, shrinkage equal to or more than the shrinkage of the casting occurs in the slide core. Therefore, it becomes easy to separate the slide core from the casting. However, there has been a problem that the material of the slide core is limited to a material suitable for a mold and having a thermal expansion coefficient equal to or higher than that of a material of a casting. Further, the method described in the above publication cannot be used to eliminate or reduce the draft of the outer peripheral surface of the cast product.

[0003]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention is directed to a casting method capable of reducing a draft angle of an inner or outer peripheral surface of a cast product, and a method suitable for the method. An object of the present invention is to provide a casting mold apparatus, and the present invention provides a casting method and a casting mold apparatus of the following embodiments. Each mode is divided into terms as in the claims, and each term is numbered,
Enter the number of another section as necessary.
This is for the purpose of facilitating the understanding of the present invention, and should not be construed as limiting the technical features and combinations thereof described in the present specification to those described in the following sections. . In addition, when a plurality of items are described in one section, the plurality of items need not always be adopted together. It is also possible to select and adopt only some items.

[0004] In the following items, (1) corresponds to claim 1, (4) to claim 2, and (5) to claim 3.
(6) corresponds to claim 4, (8) to claim 5, and (11) to claim 6.

(1) A method for casting a casting having at least one of an inner peripheral surface and an outer peripheral surface, wherein the hollow cylindrical portion has a cavity surface for molding at least one of the inner peripheral surface and the outer peripheral surface. Is closed, and a cavity having a shape corresponding to the casting is formed inside the mold, and the hollow cylindrical portion is moved to the cavity side with one of the inner peripheral surface and the outer peripheral surface facing the cavity. Elastically deform in the direction of displacement, pouring a molten metal into the cavity while maintaining the elastically deformed state, and after the molten metal solidifies, open the mold and eliminate the elastic deformation of the hollow cylindrical portion. And a method for removing a casting from a mold.

If the molten metal is poured into the cavity and solidified while the hollow cylindrical portion is elastically deformed toward the cavity,
As a result, the molded product and the hollow cylindrical portion are tightly fitted to each other. Then, if the elastic deformation of the hollow cylindrical portion is eliminated, the hollow cylindrical portion is deformed to the side opposite to the cavity side. When the outer peripheral surface of the hollow cylindrical portion is a cavity surface, the hollow cylindrical portion kept in the expanded state by elastic deformation contracts, and when the inner peripheral surface of the hollow cylindrical portion is a cavity surface, In addition, the hollow cylindrical portion, which has been kept in the contracted state by the elastic deformation, expands, so that the tight fitting state between the hollow cylindrical portion and the cast product is reduced, or the clearance fit state is obtained. Therefore, if the hollow cylindrical portion and the casting are separated from each other in this state, the casting can be easily separated, and the draft of the inner peripheral surface or the outer peripheral surface of the casting can be made smaller than before. In some cases, it is possible to completely eliminate the draft. (2) The surface of the hollow cylindrical portion opposite to the cavity surface that forms one of the inner peripheral surface and the outer peripheral surface is linearly dimensioned in a direction parallel to the central axis of the hollow cylindrical portion. A tapered member having a tapered surface corresponding to the tapered surface is prepared, and the elastic deformation of the hollow cylindrical portion is caused by tight fitting with the hollow cylindrical portion of the tapered member. The casting method according to item (1). If the tapered member and the hollow cylindrical portion are tightly fitted to each other at the corresponding tapered surfaces, the hollow cylindrical portion can be easily elastically deformed. (3) The casting method according to the above mode (1) or (2), wherein the hollow cylindrical section is a hollow cylindrical section having a circular cross section.

Although the cross section of the hollow cylindrical portion is arbitrary,
The present invention can be favorably applied to an axially symmetric shape such as a rectangular cylindrical portion having a cross-sectional shape of a regular polygon, and is particularly favorable when the cross-sectional shape is a hollow cylindrical portion having a circular shape. Results are obtained. (4) The cast product is a cylinder block having a plurality of cylinder bores of a swash plate compressor, and at least one of the inner peripheral surface and the outer peripheral surface is an inner peripheral surface of the cylinder bore. The casting method according to any one of the above items 3).

A cylinder block is a product particularly suitable for applying the present invention. However, when a plurality of cylinder bores are formed adjacent to each other, the cross section of the hollow cylindrical portion is assumed to be a perfect circle. Cylinder bores with good roundness may not be formed. In this case, it is desirable that the cross-sectional shape of the hollow cylindrical portion is slightly deviated from a perfect circle at least in an elastically deformed state, and the cylinder bore of the casting is a perfect circle. (5) The cast product is a front housing having a hollow cylindrical portion of a swash plate compressor, and at least one of the inner peripheral surface and the outer peripheral surface is an inner peripheral surface of the hollow cylindrical portion. Or a casting method according to any one of the above (3).

The front housing of a swash plate compressor often needs to have a highly accurate cylindrical inner peripheral surface, for example, having a cylindrical surface that slides with a rotation preventing portion of a piston. If this inner peripheral surface is formed according to the present invention, the required amount of machining can be reduced or machining can be omitted. (6) A mold apparatus for casting a casting having at least one of an inner peripheral surface and an outer peripheral surface, wherein the hollow cylindrical portion has a cavity surface for molding one of the inner peripheral surface and the outer peripheral surface. And a resilient deformation device for resiliently deforming the hollow cylindrical portion of the mold in a direction to displace one of the inner peripheral surface and the outer peripheral surface of the hollow cylindrical portion toward the cavity. A casting mold apparatus characterized by the above-mentioned. According to the casting mold apparatus, the casting method described in the above (1) can be performed. (7) The hollow cylindrical portion includes a pair of dies that are opened and closed by being approached and separated from each other, and the hollow cylindrical portion is provided in a posture extending in a direction parallel to the opening and closing direction of the pair of dies. Casting mold equipment.

It is possible to provide the hollow cylindrical portion in a position extending in a direction intersecting with the opening and closing direction of the mold. However, if the hollow cylindrical portion is provided in a position extending in parallel with the opening and closing direction of the mold, the hollow cylindrical portion is elastic. It becomes easy to deform, or to separate the hollow cylindrical part from the casting after the elastic deformation is eliminated. (8) The hollow cylindrical portion is formed of a member separate from the main body of the mold, and at least a portion adjacent to a portion functioning as the hollow cylindrical portion is a fitting portion formed in the main body. (6) or fitted with a radial gap left
The casting mold apparatus according to the above mode (7). The fitting portion may be a fitting hole or a fitting protrusion. The former is a case where the peripheral surface constituting the cavity surface is the outer peripheral surface, and the latter is a case where the peripheral surface constituting the cavity surface is the inner peripheral surface. In any case, if the portion adjacent to the portion functioning as the hollow cylindrical portion is fitted to the fitting portion formed on the main body while leaving a gap in the radial direction, elastic deformation of this portion is easy. Thus, it becomes easy to cause substantially uniform elastic deformation in the entire portion functioning as the hollow cylindrical portion. (9) One of the inner peripheral surface and the outer peripheral surface of the hollow cylindrical portion is an outer peripheral surface, and the elastic deformation device includes: an expansion member that contacts the inner peripheral surface of the hollow cylindrical portion; A pressing device for expanding the hollow cylindrical portion by forcibly pressing against the inner peripheral surface of the hollow cylindrical portion. The casting mold apparatus according to any one of the above modes (6) to (8). The expansion member in this section can be, for example, a taper member or a collet described later. In such a case, the pressing device becomes a tight fitting device or a collet diameter changing device. (10) One of the inner peripheral surface and the outer peripheral surface of the hollow cylindrical portion is an inner peripheral surface, and the elastic deformation device includes a reducing member that contacts an outer peripheral surface of the hollow cylindrical portion, and a reducing member that includes the reducing member. A pressing device for forcibly pressing the outer peripheral surface of the hollow cylindrical portion to reduce the hollow cylindrical portion, the casting die device according to any one of the above items (6) to (8). The reduction member of this section is, for example,
A taper member or a collet described later can be used. In such a case, the pressing device becomes a tight fitting device or a collet diameter changing device. (11) The surface of the hollow cylindrical portion opposite to the cavity surface that forms one of the inner peripheral surface and the outer peripheral surface gradually changes in dimension in a direction parallel to the center axis of the hollow cylindrical portion. A taper member having a taper surface corresponding to the taper surface is provided, and the elastic deformation device tightens the taper member and the taper member to the taper surface of the hollow cylindrical portion. Interference fitting device
The casting mold apparatus according to any one of the above modes (6) to (8). This casting mold apparatus is suitable for carrying out the casting method of the above item (2). (12) The tapered member is held by the main body of the mold so as to be movable in the axial direction, and the interference fitting device includes an axial moving device that moves the tapered member in the axial direction.
The casting mold apparatus according to item 1). This aspect is particularly effective when the hollow cylindrical portion and the tapered member are provided in a position intersecting the opening and closing direction of the mold, but can also be adopted when the hollow cylindrical portion and the tapered member are provided in a position parallel to the opening and closing direction of the mold. . (13) The casting mold apparatus according to the mode (12), wherein the axial moving device includes a hydraulic cylinder fixed to the mold. (14) The taper member is fixed to a mold of the pair of dies opposite to the side on which the hollow cylindrical portion is provided, and an opening / closing device that opens and closes the pair of dies is the tight fitting. The casting mold apparatus according to item (11), which also functions as an apparatus. (15) An ejector device that pushes a cast product from the mold and separates the hollow tubular portion from the cast product in a mold of the pair of molds on which the hollow tubular portion is provided. The casting mold apparatus according to any one of the above modes (7) to (14).

If the ejector device is provided, it becomes easy to separate the hollow cylindrical portion from the casting. In particular, if the ejector device is operated after the elastic deformation of the hollow cylindrical portion is eliminated, the hollow cylindrical portion and the casting can be easily separated. It is particularly effective to employ the features of this section together with the features of section (14). At the same time when the pair of molds is opened, the tapered member and the hollow cylindrical portion are separated from each other, the elastic deformation of the hollow cylindrical portion is eliminated, and the separation between the hollow cylindrical portion and the casting is facilitated. This is because the ejector device can be operated to separate the hollow cylindrical portion from the casting. (16) The hollow cylindrical portion is a hollow cylindrical portion having an annular cross-sectional shape, and the elastic deformation device is configured to move one of the inner peripheral surface and the outer peripheral surface of the hollow cylindrical portion. A collet fitted with a surface opposite to the cavity surface to be molded, and a collet diameter changing device that presses against the opposite surface by mechanically changing the diameter of the collet.
The casting mold apparatus according to the above mode (6).

Here, the collet is obtained by dividing a hollow cylindrical member into a plurality in the circumferential direction, and can be easily expanded or contracted. However, when the gap between the plurality of divided members is large, the amount of elastic deformation of the hollow cylindrical portion is reduced at a portion corresponding to the gap, and the outer circumferential surface or the inner circumferential surface of the hollow cylindrical portion is a perfect circle. And the roundness of the inner or outer peripheral surface of the cast product also deteriorates.
It is desirable to make the gap as small as possible. Although a plurality of members may be completely separated from each other in the collet, it is preferable that a part of the collet be integrally connected for convenience of handling. (17) The surface of the collet opposite to the surface fitted with the hollow cylindrical portion is a first tapered surface whose diameter linearly and gradually changes in the axial direction. A taper member having a second taper surface corresponding to the first taper surface, and at least a state in which the first taper surface and the second taper surface are fitted to each other, between the collet and the taper member, The first and second tapered surfaces are moved by axially moving the tapered member and the hollow cylindrical portion relative to each other while maintaining a relative position and being rotatable individually. The casting mold apparatus according to the above mode (16), further comprising: an axial moving device that is tightly fitted via the ball.

A large number of balls are rotatably held in ball receiving recesses formed on one of the first tapered surface and the second tapered surface in a state where they are partly projected to the outside. The tapered surface and the second tapered surface may be brought into contact with each other, and can be rotated by a retainer independent from both the tapered member and the hollow cylindrical portion and held in a state of protruding outside from both surfaces of the retainer. It may be so arranged that the first tapered surface and the second tapered surface are interposed and roll between them. In any case, the friction when the tapered member and the hollow cylindrical portion are tightened and fitted is reduced,
The effect of improving the durability of the mold device is obtained.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A swash plate type compressor manufactured using a casting mold apparatus according to an embodiment of the present invention and manufactured by a casting method according to an embodiment of the present invention will be described below with reference to the drawings. This will be described in detail. FIG. 1 shows a swash plate type compressor used in an automotive air conditioner according to the present embodiment. Figure 1
2 and 10, reference numeral 10 denotes a cylinder block;
On one circumference around the central axis L of the cylinder block 10, a plurality (7 in the illustrated example) extending parallel to the central axis L is provided.
) Are formed at equal angular intervals. Each of the cylinder bores 12 has a single-headed piston 14
(Hereinafter, abbreviated as piston 14) is provided so as to be able to reciprocate. A front housing 16 is mounted on one axial end surface of the cylinder block 10 (the left end surface in FIG. 1 and referred to as a front end surface), and the other end surface (the right end surface in FIG. 1 and a rear end surface). ), A rear housing 18 is mounted via a valve plate 20. Front housing 16, Rear housing 1
8, the housing of the swash plate type compressor is constituted by the cylinder block 10 and the like. A suction chamber 22 and a discharge chamber 24 are formed between the rear housing 18 and the valve plate 20, and are connected to a refrigeration circuit (not shown) via a suction port 26 and a supply port 28, respectively. The valve plate 20 has a suction hole 32, a suction valve 34, a discharge hole 3
6, a discharge valve 38 and the like are provided.

A rotary shaft 50 is provided in the housing so as to be rotatable about a central axis L of the cylinder block 10 as a rotational axis. The rotating shaft 50 is rotatably supported at both ends thereof by the front housing 16 and the cylinder block 10 via bearings. A support hole 56 is formed in the center of the cylinder block 10 and is supported in the support hole 56 via the bearing. The end of the rotary shaft 50 on the front housing 16 side is connected to a vehicle engine as a drive source (not shown) via a clutch device such as an electromagnetic clutch. Therefore, when the rotating shaft 50 is connected to the vehicle engine by the clutch device during the operation of the vehicle engine, the rotating shaft 50 is rotated around its own axis.

A swash plate 60 is attached to the rotating shaft 50 so as to be relatively movable and tiltable in the axial direction. Swash plate 60
, A through hole 61 passing through the center line is formed, and the rotating shaft 50 passes through the through hole 61. The inner diameter of the through-hole 61 is gradually increased in the up-down direction in FIG. 1 as the both ends are opened, and the cross-sectional shape of each of the both ends forms an elongated hole. A rotating plate 62 is also fixed to the rotating shaft 50, and is received by the front housing 16 via a thrust bearing 64. The swash plate 60 is moved by the hinge mechanism 66.
In addition to being rotated integrally with the rotating shaft 50, tilting accompanied with axial movement is allowed. The hinge mechanism 66 includes a support arm 67 fixedly provided on the rotating plate 62 and a swash plate 6.
0, and the guide hole 68 of the support arm 67 is provided.
Guide pin 69 slidably fitted to the swash plate 6
0 and the outer peripheral surface of the rotating shaft 50.

The piston 14 has an engaging portion 70 that is engaged with the swash plate 60 so as to straddle the outer peripheral portion thereof, and a head 7 that is provided integrally with the engaging portion 70 and that is fitted into the cylinder bore 12.
2 is provided. The head 72, the cylinder bore 12, and the valve plate 20 together form a compression chamber.
Further, the engaging portion 70 is engaged with the outer peripheral portion of the swash plate 60 via a pair of spherical-shaped shoes 76.

The rotational movement of the swash plate 60 is converted into a reciprocating linear movement of the piston 14 via the shoe 76. In the suction stroke in which the piston 14 moves from the top dead center to the bottom dead center,
The refrigerant gas in the suction chamber 22 is supplied to the suction hole 32 and the suction valve 34.
Through the cylinder bore 12. Piston 14
In the compression stroke in which the refrigerant moves from the bottom dead center to the top dead center, the refrigerant gas in the cylinder bore 12 is compressed and discharged to the discharge chamber 24 through the discharge hole 36 and the discharge valve 38. An axial compression reaction force acts on the piston 14 as the refrigerant gas is compressed. The compression reaction force is received by the front housing 16 via the piston 14, the swash plate 60, the rotating plate 62, and the thrust bearing 64. Engaging part 7 of piston 14
The rotation prevention unit (not shown) is integrally provided at 0. The anti-rotation portion restricts the rotation of the piston 14 around the central axis by coming into contact with the inner peripheral surface of the front housing 16 and avoids interference between the piston 14 and the swash plate 60.

An air supply passage 80 is provided through the cylinder block 10. The discharge chamber 24 and the swash plate chamber 86 formed between the front housing 16 and the cylinder block 10 are connected by the air supply passage 80. An electromagnetic control valve 90 is provided in the middle of the air supply passage 80. The current supply to the solenoid 92 of the electromagnetic control valve 90 is controlled by a control device (not shown) mainly composed of a computer in accordance with information such as a cooling load.

A discharge passage 100 is provided inside the rotary shaft 50. The discharge passage 100 has one end opened to the support hole 56 and the other end opened to the swash plate chamber 86. The support hole 56 is communicated with the suction chamber 22 via the discharge port 104.

The swash plate type compressor is of a variable displacement type, and the pressure in the swash plate chamber 86 is controlled by utilizing the pressure difference between the discharge chamber 24 on the high pressure side and the suction chamber 22 on the low pressure side. The difference between the pressure in the compression chamber in the cylinder bore 12 acting before and after the piston 14 and the pressure in the swash plate chamber 86 is adjusted,
The inclination angle of the swash plate 60 is changed, the stroke of the piston 14 is changed, and the displacement of the compressor is adjusted. Specifically, the pressure of the swash plate chamber 86 is controlled by controlling the excitation and demagnetization of the electromagnetic control valve 90 so that the swash plate chamber 86 is communicated with the discharge chamber 24 or cut off.
The maximum inclination angle of the swash plate 60 is defined by the contact of the stopper 106 provided on the swash plate 60 with the rotary plate 62, and the minimum inclination angle is the contact of the swash plate 60 with the stopper 107 on the rotation shaft 50. Defined by

Between the swash plate 60 and the rotary plate 62, a compression coil spring 108 as an elastic member, which is a kind of a biasing device, is disposed. Are biased toward a position that is substantially perpendicular to the center axis of the. When the operation of the compressor is stopped, the swash plate 60 is brought into contact with the stopper 107 by the urging force of the spring 108 and enters a state of waiting for restart.

Cylinder block 10 and piston 14
Is made of an aluminum alloy, which is a kind of metal, and the outer peripheral surface of the piston 14 is coated with a fluororesin. By coating with a fluororesin, the fitting gap with the cylinder bore 12 can be reduced as much as possible while avoiding direct contact with the same kind of metal and preventing seizure. However, the material of the cylinder block 10 and the piston 14, the material of the coating layer, and the like are not limited to the above-described materials, and may be other materials.

As shown in FIG. 2, the cylinder block 10 has a peripheral wall defining each of the cylinder bores 12 in which an outer peripheral portion farther from the central axis L is inclined more than an inner peripheral portion closer to the central axis L. An extension 150 that extends long in the axial direction toward the plate chamber 86 is integrally formed. The front end surfaces 152 of the extending portions 150 are connected to each other so as to be positioned on the same plane, and the front housing 16
Is attached. The inner peripheral surface of the cylinder bore 12
Inner peripheral surface 15 that forms a complete cylindrical surface on the side of rear housing 18
4 and an inner peripheral surface 156 that forms a partial cylindrical surface on the front housing 16 side. When the extension 150 is provided to increase the length of the outer peripheral side (the side far from the center axis L) of the peripheral wall of the cylinder bore 12, the outer peripheral side between the piston 14 and the cylinder bore 12 at the bottom dead center of the piston 14 is increased. The fitting length can be lengthened, whereby the inclination of the piston 14 in the direction in which the engaging portion 70 moves to the outer peripheral side is satisfactorily avoided. To prevent the swash plate 60 from returning to the minimum inclination angle. Note that the inner peripheral side of the cylinder bore 12 (the side closer to the center axis L) does not have the extension 150, and
The movement of the swash plate 60 from the maximum inclined position to the minimum inclined position is not hindered.

A method of manufacturing the cylinder block 10 configured as described above will be described. The cylinder block 10 in the present embodiment is manufactured by casting. FIG. 3 is a schematic view of a casting apparatus including a casting mold apparatus used in the present casting method. Body frame 20 of casting apparatus 200
2, a pair of fixed boards 204 and 206 are provided to face each other.
Both ends of the guide rod 208 are fixed.
The four guide rods 208 are arranged in parallel with each other, and a movable plate 210 is slidably supported by the guide rods 208. The fixed platen 204 is provided with an opening / closing cylinder 214 constituting a mold clamping device. The opening / closing cylinder 214 is a hydraulic cylinder which is a type of a fluid pressure cylinder, and the cylinder housing 216 of the opening / closing cylinder 214 is held in a liquid-tight state on the opposite side of the fixed plate 204 to the movable plate 210 side. Installed. A piston rod 220 provided integrally with a piston 218 slidably and slidably fitted in the cylinder housing 216 penetrates through the fixed plate 204 and protrudes toward the movable plate 210. It is connected to. The movable platen 210 is moved by the opening / closing cylinder 214.
Is moved toward and away from the fixed platen 206 while being guided by the guide rod 208. The separation limit of the movable platen 210 is specified by a separation limit specifying device (not shown).

The surfaces of the fixed plate 206 and the movable plate 210 facing each other are fixed 224 and movable plate 22 respectively.
6 are detachably attached. The casting mold apparatus includes the fixed mold 224 and the movable mold 226. Although not shown in detail, the fixed mold 224 is formed by stacking a plurality of plate-like members, and includes a fixed mold plate, a fixed mounting plate, and the like, and is attached to the fixed plate 206 at the fixed mounting plate. Have been. Like the fixed mold 224, the movable mold 226 also includes a plurality of plate-shaped members, includes a movable mold plate, a movable mounting plate, and the like, and is attached to the movable plate 210 at the movable mounting plate. The fixed die 224 and the movable die 226 are respectively provided with a fixed plate 206 and a movable plate 21
It is attached in a state where it is accurately positioned with respect to zero. For example, by engaging engagement protrusions provided integrally with the fixed mold 224 and the movable mold 226 with engagement grooves provided on the fixed board 206 and the movable board 210, respectively, the precision is improved. Well positioned. Fixed type 22
4 and one of the movable molds 226 are provided with positioning pins,
A pin hole is formed on the other side, and the fixed plate 206 and the movable plate 210
It is also possible to make it attach to.

The fixed mold 224 and the movable mold 226 are shown in FIG.
As shown in the figure, the movable mold 2 can be opened and closed on the parting surfaces 230 and 232 which are surfaces facing each other.
The fixed mold 22 is driven by the driving force of the opening / closing cylinder 214.
4 and the parting surfaces 230, 23
The two are brought into close contact. These parting surfaces 23
In a state where 0, 232 are brought into close contact with each other, the mold 224,
Inside the 226, a cavity 236 having a shape corresponding to the outer shape of the cylinder bore 12, which is a casting, is formed. Cavity surfaces 240, 242 are respectively formed at positions corresponding to each other on each of the parting surfaces 230, 232,
The outer shape of the cylinder block 10 is defined by the cavity surfaces 240 and 242. The cylinder block 10 is cast by injecting a molten metal (in this embodiment, an aluminum alloy which is a material mainly composed of aluminum) into the cavity 236.

The lower end of the cavity 236 is communicated with a sleeve 250 having a pouring port (see FIG. 3) through a runner extending parallel to the parting surfaces 230 and 232. At the end of the runner on the cavity 236 side, a gate having a smaller cross-sectional area than other portions is formed. The sleeve 250 has a cylindrical shape, extends outward from the fixed mold 224, and is supported by the fixed platen 206. Sleeve 25
The plunger 2 provided at the tip of the plunger 252 is provided in a portion that extends through the fixed plate 206
A plunger tip 254 larger than 52 is slidably fitted. The plunger 252 is integrally movably connected to a piston rod 258 of a plunger driving cylinder 256 as an example of a plunger driving device. The plunger driving cylinder 256 is a hydraulic cylinder, which is a type of hydraulic cylinder, and
2 is immovably supported. These sleeves 25
0, plunger 252, plunger tip 254, cylinder for driving plunger 256, piston rod 258
However, this constitutes an injection device for injecting the molten aluminum alloy poured from the pouring port into the cavity 236.

An ejector device 260 is provided inside the movable mold 226. The ejector device 260 includes an extrusion cylinder 262 (see FIG. 3) and a plurality of extrusion pins 2.
64 (see FIG. 4). The extrusion cylinder 262 is a hydraulic cylinder which is a type of a hydraulic cylinder, and is mounted at a position where it does not interfere with other members of the movable mold 226. When the piston rod 268 is extended by driving the pushing cylinder 262, the pushing member 266 is pushed out and the pushing pin 26
4 from the retracted end position that defines cavity 236 in cooperation with cavity surface 242.
The casting is protruded into and advanced to an advanced end position for extruding the cast product. When the piston rod 268 is contracted, the pushing member 266 is retracted. The forward and backward limits of the pushing member 266 are, for example, the pushing member 266.
Front and rear surfaces in the forward and backward directions of the
Are defined by the contact of the fitting holes, which are fitted forward and backward, respectively, with the shoulder surfaces.

The opening / closing cylinder 214, the plunger driving cylinder 256, the pushing cylinder 262 and the like are controlled by a control device (not shown) provided with a computer. Specifically, a directional control valve or the like provided in a liquid passage connected thereto is controlled by a control device.

As shown in FIG. 4, the movable mold 226 is integrally provided with a hollow cylindrical portion 280. Specifically, the movable main body 283 constituting the main body of the movable mold 226
The hollow cylindrical member 2 separate from the movable body 283
82 is attached so as to be relatively immovable by fixing means in a state where its axial direction is parallel to the opening and closing direction of the fixed mold 224 and the movable mold 226, and is axially moved from the cavity face 242 at one end (tip end) thereof. The protruding portion functions as a hollow cylindrical portion 280 whose diameter can be expanded or reduced by elastic deformation. The distal end surface of the hollow cylindrical member 282 is located on the same plane as the parting surface 232 of the movable mold 226. The material for forming the hollow cylindrical member 282 is alloy tool steel (SK of JIS) generally used as a mold material.
D-type tool steel, for example, SKD61) is suitable. It is also desirable that at least a portion of the fixed mold 224 and the movable mold 226 forming the cavity 236 is formed of tool steel such as alloy tool steel.

In the illustrated example, the hollow cylindrical member 28
2 has a rear end portion opposite to the hollow cylindrical portion 280 side, and has a fitting hole 2 formed in the movable body 283 in parallel with the opening and closing direction.
84. An engaging portion 290 having a larger diameter than other portions of the engaging pin 288 is engaged with a shoulder surface 286 formed on the stepped inner peripheral surface of the hollow cylindrical portion 280, and the engagement of the engaging pin 288 is performed. The hollow cylindrical member 282 is attached to the attachment member 294 by tightening the nuts 292 and 293 on the screw portion formed on the rear end protruding from the movable mold body 283 on the side opposite to the joint 290 side. An attachment member 294 is fixed to the movable main body 183.

The fitting hole 284 has a large-diameter hole 296 whose end on the cavity surface 242 side is slightly larger in diameter than other portions. In an inelastic deformation state, the outer peripheral surface of the hollow cylindrical member 282 forms a cylindrical surface having a constant diameter in the axial direction as shown by a two-dot chain line in FIG. The outer peripheral surface of the portion adjacent to the portion that functions as the inner peripheral surface of the large-diameter hole portion 296 is fitted with a small gap in the radial direction. The outer peripheral surface of the hollow cylindrical portion 280 forms a cavity surface 300 that forms the inner peripheral surface of the cylinder bore 12 of the cylinder block 10. That is, the cavity surface 240 of the fixed mold 224 and the movable mold 22
The cavity 236 corresponding to the shape of the cylinder block 10 is defined by the cavity surface 242 of No. 6 and the cavity surface 300 of the hollow cylindrical portion 280. FIG. 4 representatively shows one of the hollow cylindrical portions 280 for forming the inner peripheral surfaces of the plurality (seven in the present embodiment) of the cylinder bores 12. The inner peripheral surface of the hollow cylindrical portion 280 has an opening side (fixed type 224) in a direction parallel to the central axis of the hollow cylindrical portion 280.
The tapered inner peripheral surface 304 increases linearly toward the side.

The fixed die 224 is integrally provided with a tapered member 310. The taper member 310 is movable type 2
It is provided coaxially at a position facing the 26 hollow cylindrical portion 280. The tapered member 310 is a shaft-shaped member, and is immovably attached to a fixed main body 312 which is a main body of the fixed die 224 by a fixing means. A fitting hole 314 extending in the axial direction is formed in the solid type main body 312,
An end of the fitting hole 314 on the side opposite to the movable die 226 side is a female screw hole 316. A screw portion 320 is integrally provided at one end of the tapered member 310, and the screw portion 320 is screwed into the female screw hole 316, whereby the tapered member 310 is fixed to the fixed mold 224. However, the fixing means may be of another form. For example, the fixing means may be immovably attached by press-fitting the tapered member 310 into the fitting hole of the fixed mold 224. The end of the tapered member 314 on the screw portion 320 side has a head 322 having a larger diameter than the other portions, and the screw portion 320 is tightened until the end surface of the head 322 and the end surface of the fixed mold 224 come into contact with each other. In this state, an end (tip) opposite to the screw portion 320 is projected from the parting surface 230 and the cavity surface 240 of the fixed mold 224 toward the movable mold 226. The outer peripheral surface at the distal end of the tapered member 314 is a tapered outer peripheral surface 326 corresponding to the tapered inner peripheral surface 304.

When the movable mold 226 is brought closer to the fixed mold 224 and the parting surfaces 230 and 232 are brought into close contact with each other, the tapered inner peripheral surface 304 of the hollow cylindrical portion 280 and the tapered outer peripheral surface 326 of the tapered member 310 are formed. Tight fitting
The hollow cylindrical portion 280 and the portion adjacent to the hollow cylindrical portion 280 are elastically deformed to the outer peripheral side, and the outer peripheral surface is enlarged (see FIG. 4). However, FIG. 4 exaggerates the amount of elastic deformation of the hollow cylindrical portion 280 for easy understanding. The portion adjacent to the hollow cylindrical portion 280 is enlarged in the large-diameter hole 296, and the outer peripheral surface thereof is brought into close contact with the inner peripheral surface of the large-diameter hole 296, whereby the cavity surface 242 of the fitting hole 284 is formed. The opening on the side is sealed, and communication with the cavity 236 is shut off. In addition, even when the tapered member 310 is pressed into the hollow cylindrical portion 280, the distal end surface of the tapered member 310 and the hollow cylindrical portion 280 are pressed.
The axial lengths of the hollow cylindrical portion 280 and the tapered member 310 are set so that a gap remains in the axial direction with the engaging portion 290 of the engaging pin 288 engaged with the engaging pin 288. Also, the movable mold 226 is separated from the fixed mold 224,
When the tapered member 310 is detached from the hollow cylindrical portion 280, the elastic deformation of the hollow cylindrical portion 280 is eliminated.

A casting method using the casting apparatus 200 having the casting mold apparatus configured as described above will be described. First, the opening / closing cylinder 214 is driven, the movable mold 226 is brought close to the fixed mold 224, and the mold is clamped in a state where the parting surfaces 230 and 232 are in close contact with each other. With the movable mold 226 and the fixed mold 224 closed, a cavity 236 is formed inside the molds 224 and 226. At this time, the tapered inner peripheral surface 304 of the hollow cylindrical portion 280 and the tapered outer peripheral surface 326 of the tapered member 310 are tightly fitted to each other, so that the hollow cylindrical portion 280 is formed.
Is elastically deformed toward the cavity 236. As described above, the fitting hole 284 of the movable mold 226 is sealed off from the cavity 236. Mold 22
In a state in which 4,226 is closed, the internal space of the sleeve 250 communicates with the cavity 236 via the runner. In addition, the plunger tip 254 is positioned at a retracted end position that allows the pouring port of the sleeve 250 to communicate with the cavity 236, and a molten metal (for example, an aluminum alloy) is supplied into the sleeve 250 from the pouring port. Thereafter, the plunger tip 254 is advanced toward the fixed mold 224 and the movable mold 226, and the molten metal level in the sleeve 250 is raised. Eventually, the molten metal enters the runner. At this point, the forward speed of the plunger tip 254 is increased, and the molten metal is ejected at a stretch into the cavity 236 through the narrow gate. Even after the cavity 236 is filled with the molten metal, the plunger tip 254 continues to be driven, and the molten metal in the cavity 236 is solidified under a sufficient pressure.

After the filling of the melt into the cavity 236 is completed, the cylinder block 10 as a casting is waited for solidification for a set time. The inner peripheral surface of the cylinder bore 12 of the cylinder block 10 is formed by a cavity surface 300 which is an outer peripheral surface of the hollow cylindrical portion 280 maintained in an expanded state by elastic deformation. The movable mold 226 is the fixed mold 224
The molds 224 and 226 are opened by being separated from the molds. At the same time, the hollow cylindrical portion 280 also has a tapered member 310.
The tapered inner peripheral surface 304 of the hollow cylindrical portion 280 and the tapered outer peripheral surface 3 of the tapered member 310
26 is released, and the elastic deformation of the hollow cylindrical portion 280 is eliminated. The hollow cylindrical portion 280 is deformed (shrinks) on the opposite side to the cavity 236, contrary to the time of mold clamping.
As a result, a radial gap is created between the cavity surface 300 of the hollow cylindrical portion 280 and the inner peripheral surface of the cylinder bore 12 of the cast cylinder block 10.
The inner peripheral surface 2 and the cavity surface 300 are in a tight fitting state from a tight fitting state. And the cylinder 2 for extrusion
By driving the cylinder 62, the cylinder block 10 held by the movable mold 226 is pushed out by the advance of the push pin 264. As described above, since the tight fit between the inner peripheral surface of the cylinder bore 12 and the cavity surface 300 is reduced and the clearance fit state is established, the cylinder block 10 is moved to the movable mold 2.
26 can be easily separated.

As is clear from the above description, the present embodiment is a case where the peripheral surface constituting the cavity surface is the outer peripheral surface, and the hollow cylindrical portion 280 is an example of the hollow cylindrical portion. The tapered inner peripheral surface 304 is a tapered surface whose dimension linearly changes in a direction parallel to the central axis of the hollow cylindrical portion, and the tapered outer peripheral surface 326 is a tapered surface corresponding to the tapered surface. The fitting hole 284 is an example of a fitting portion. The fixed mold 224 and the movable mold 226 are an example of a pair of molds which are components of the casting mold apparatus and are opened and closed by being approached and separated from each other. The opening / closing cylinder 214 for moving the taper member 310 in the axial direction constitutes an axial moving device which is an example of the tight fitting device. The opening / closing cylinder 214 is also an opening / closing device for opening / closing the fixed mold 224 and the movable mold 226, and the opening / closing cylinder 214 in the present embodiment serves as both the opening / closing device and the above-mentioned tight fitting device. The tapered member 310 is
0 is an example of an expanding member that comes into contact with the inner peripheral surface of the hollow cylindrical portion 280. The opening / closing cylinder 214 as the interference fitting device forcibly presses the expanding member against the inner peripheral surface of the hollow cylindrical portion 280. A pressing device for expanding the cylindrical portion 280 is configured.

According to the present embodiment, even if the draft angle of the hollow cylindrical portion 280 which is a member for forming the inner peripheral surface of the cylinder bore 12 is reduced or the draft angle is completely eliminated, The cylinder block 10 can be detached from the movable mold 226 without any trouble, and the machining cost of the inner peripheral surface of the cylinder bore 12 can be reduced after molding, or the machining process is not required, and the manufacturing cost of the compressor is reduced. You. The outer diameter and the amount of elastic deformation of the hollow cylindrical portion 280 can be appropriately set according to the desired size of the inner peripheral surface.

The hollow cylindrical portion 280 may be provided on the fixed mold 224, and the tapered member 310 may be provided on the movable mold 226.
Further, the taper member 310 may be movable in the axial direction separately from the mold by a driving device such as a hydraulic cylinder provided separately from the opening / closing cylinder 214.

The casting mold apparatus and the casting method using the same according to the present invention may be applied to casting of a casting other than the cylinder block 10. An example in which the front housing 16 having the hollow cylindrical portion of the swash plate type compressor is manufactured will be described with reference to FIG. FIG. 5 schematically shows a mold apparatus for casting the front housing 16. The structure of the entire casting apparatus including this mold apparatus is shown in FIG.
Can be the same as the casting apparatus 200 shown in FIG. The mold apparatus includes a fixed mold 400 and a movable mold 402 which are opened and closed by being approached and separated from each other, as in the above-described embodiment. Although the detailed illustration of the fixed mold 400 and the movable mold 402 is omitted,
Both are formed by stacking a plurality of plate-like members.
The movable mold 402 is moved toward and away from the fixed mold 400 by an opening / closing drive device (for example, a hydraulic cylinder) (not shown), and is brought into close contact with the parting surfaces 404 and 406 which are surfaces facing each other. . Fixed type 40
At 0, a hollow cylindrical member 408 is integrally provided in a state extending in a direction parallel to the approaching and separating directions (axial directions) of the fixed mold 400 and the movable mold 402. Hollow cylindrical member 40
Reference numeral 8 denotes a hollow cylindrical portion 410 extending in the axial direction from the parting surface 404 and a portion adjacent to the hollow cylindrical portion 410, and is axially inserted into a fitting hole 412 of a fixed type main body 411 which is a main body of the fixed type 400. Fitting part 41 which is immovably fitted to
4 is provided. The fitting portion 414 has a flange portion 416 whose end is larger in diameter than other portions. Fixed type main body 41
The one fitting hole 412 has a stepped shape in which the opposite side to the parting surface 404 is a large-diameter hole. The diameter of the inner peripheral surface of the small-diameter hole on the parting surface 404 side of the fitting hole 412 is smaller than the diameter of the outer peripheral surface of the flange portion 416. The hollow cylindrical member 408 is inserted from the large-diameter hole side of the fitting hole 412 with the hollow cylindrical portion 410 side as the tip end, and the flange portion 416 and the shoulder surface of the fitting hole 412 come into contact with each other to form the hollow cylindrical portion. The protrusion limit of the part 410 from the parting surface 404 is defined, and the holding member 417 is fitted from the large-diameter hole side and fixed to the fixed-type main body 411 by bolts as fixing means. 408 is prevented from being pulled out of the fixed main body 411. Holding member 41
7 functions as a part of the fixed main body after fixing. The fitting portion 414 is fitted in the fitting hole 412 with a radial gap left in a non-elastic deformation state, as shown by a two-dot chain line in FIG. The outer peripheral surface of the hollow cylindrical member 410 forms a cylindrical surface having a constant diameter in the axial direction, and forms a cavity surface 420 that forms the inner peripheral surface of the front housing 16. The cavity surface 420 together with the cavity surfaces 422 and 424 of the main bodies 411 and 421 of the fixed mold 400 and the movable mold 402 define a cavity 426 corresponding to the shape of the front housing 16. The cavity surface 424 defining the outer surface of the front housing 16 of the movable mold 402 has a draft angle in the axial direction. The inner peripheral surface of the hollow cylindrical member 408 is a tapered inner peripheral surface 428 whose diameter gradually changes linearly in a direction parallel to the central axis thereof, and whose diameter on the movable mold 402 side becomes the maximum.

The lower end of the cavity 426 passes through a runner 430 extending parallel to the parting surfaces 404 and 406.
It is communicated with a sleeve having a pouring port. Hot spring 4
A gate 432 having a smaller cross-sectional area than other portions is formed at the end of the cavity 30 on the side of the cavity 426. In this embodiment, an injection device including a sleeve, a plunger, a plunger tip, a plunger driving device, and the like having the same configuration as the above embodiment is also provided, but illustration and description thereof are omitted in this embodiment. An ejector device (not shown) having the same configuration as the ejector device 260 is provided inside the movable mold 402.

The fixed die 400 includes a hollow cylindrical member 408.
The tapered member 440 is provided so as to be able to move in the internal space in the axial direction. The tapered member 440 is a shaft-shaped member, and is disposed coaxially with the hollow cylindrical portion 410. The outer peripheral surface of the distal end, which is the end on the hollow cylindrical portion 410 side, of the tapered member 440 is a tapered outer peripheral surface 444 corresponding to the tapered inner peripheral surface 428. Taper member 44
Numeral 0 is connected to a piston rod 446 of a taper member moving cylinder (not shown) fixed to the fixed die 400. The taper member moving cylinder is a hydraulic cylinder which is a type of actuator.

After the movable mold 402 is moved closer to the fixed mold 400 and the parting surfaces 404 and 406 are brought into close contact with each other, the cylinder for moving the taper member is driven, and the taper member 440 advances in the hollow cylindrical member 408. The tapered inner surface 428 of the hollow cylindrical portion 410 and the tapered member 4
The hollow cylindrical portion 410 and the portion adjacent to the hollow cylindrical portion 410 (the entire hollow cylindrical member 408) are elastically deformed to the outer peripheral side to expand the outer peripheral surface. Diameter. Hollow cylindrical part 41
The diameter of the portion adjacent to 0 is enlarged in the fitting hole 412, and the outer peripheral surface thereof is brought into close contact with the inner peripheral surface of the fitting hole 412. Then, the communication with the cavity 426 is cut off. At the same time, the tapered member 440 cannot advance any further, and in this state, the distal end surface of the tapered member 440 is located on the same plane as the distal end surface of the hollow cylindrical portion 410. While maintaining the elastic deformation state of the hollow cylindrical portion 410, the cavity 4
A molten metal (for example, aluminum alloy) is injected into 26. After the injected molten metal is solidified and before the fixed mold 400 and the movable mold 402 are opened, the tapered member 4
By being retracted and separated from the tapered inner peripheral surface 428 of the hollow cylindrical portion 410, elastic deformation of the hollow cylindrical member 408 including the hollow cylindrical portion 410 is eliminated, and the hollow cylindrical portion 410 contracts. As a result, a radial gap is formed between the cavity surface 420 and the inner peripheral surface of the hollow cylindrical portion of the front housing 16 as a casting. afterwards,
The movable mold 402 is separated from the fixed mold 400. At this time, the front housing 16 is held by the movable mold 402 and separated from the fixed mold 400, and the movable mold 402 and the fixed mold 40
After the “0” is fully opened, it is pushed away from the movable mold 402 by the ejector device.

The front housing 16 manufactured as described above is formed with a through hole through which the rotating shaft 50 passes. The through hole may be formed by machining after casting, or may be formed at the time of casting. It may be molded together with other parts. In the latter case, it may be formed by a shaft-shaped member provided with a tapered draft, or formed by a mold device having a hollow cylindrical portion and an elastic deformation device as described in the present embodiment. You may. In the latter case, the draft can be eliminated or reduced.

The fixing means for fixing the hollow cylindrical portion 410 to the fixed type main body 411 may be the fixing means described in the embodiment shown in FIGS. Further, in the above embodiment, the fixing means of the hollow cylindrical portion 280 to the movable mold 226 may be the fixing means in the present embodiment. Hollow cylindrical portion 410 and tapered member 440
May be provided on the movable mold 402. The ejector device may be provided on the fixed die 400 or on the movable die 402.

According to the casting method and the casting mold apparatus used therein according to the present invention, a through hole penetrating in the axial direction like the inner peripheral surface of the cylinder bore 12 in the embodiment shown in FIGS. The inner peripheral surface can be formed, or the inner peripheral surface of a concave portion having a bottom can be formed like the inner peripheral surface of the front housing 16 in the embodiment shown in FIG.

An embodiment in which the peripheral surface forming the cavity surface is the inner peripheral surface will be described with reference to FIGS. As shown in FIG. 6, the casting mold apparatus according to the present embodiment includes a fixed mold 500 and a movable mold 50 that are opened and closed by being moved toward and away from each other, as in the above-described embodiments.
2 is provided. The structure of the entire casting apparatus including this mold apparatus can be the same as that of the casting apparatus 200 shown in FIG. Although not shown in detail, the fixed mold 500 and the movable mold 502 are each formed by stacking a plurality of plate members. The movable mold 502 is moved toward and away from the fixed mold 500 by an opening / closing drive device (for example, a hydraulic cylinder) (not shown), and a parting surface 504 on which the two molds 500 and 502 face each other. , 506.

The movable mold 502 is integrally provided with a hollow cylindrical portion 510 extending in a direction parallel to the approaching and separating directions (axial directions) of the fixed mold 500 and the movable mold 502. The movable body 511, which is the body of the movable mold 502, includes:
A flat mounting portion 514 of the hollow cylindrical member 512 is immovably mounted by an appropriate fixing means such as a bolt, and is fixed in the axial direction from the inner peripheral edge of the mounting portion 514.
A hollow cylindrical portion 510 having a ring-shaped cross section extending to the zero side is provided. Hollow cylindrical member 512
Is fitted with a fitting member 520. The fitting member 520 has a rear end portion opposite to the hollow cylindrical portion 510 as a mounting portion 522 having a larger diameter than other portions. In this mounting portion 522, similarly to the hollow cylindrical member 512, a movable mold is used. It is fixed to the main body 511.

The outer peripheral surface at the distal end of the fitting member 520 is a tapered outer peripheral surface 524 having a diameter gradually reduced toward the distal end. The hollow cylindrical portion 510 can be expanded or reduced in diameter by elastic deformation. In a state where the hollow cylindrical portion 510 is not elastically deformed, there is a radial gap between the hollow cylindrical portion 510 and the tip of the fitting member 520. Are formed. Hollow cylindrical part 510
Of the movable mold 50 and the inner peripheral surface of the
The two cavity surfaces 530 and 532 are formed. On the other hand, the parting surface 504 of the fixed mold 500 is integrally provided with a protrusion 536 protruding in the axial direction toward the movable mold 502, so that the fixed mold 500 and the movable mold 502 are closely attached to the parting surfaces 504 and 506. In this state, the protrusion 536 is arranged so as to be located in the internal space formed by the cavity surfaces 530 and 532, and the protrusion 53
6 have cavity surfaces 538, 539.
Is composed. Therefore, these cavity surfaces 53
0, 532, 538, 539, etc., define a cavity 540 corresponding to the shape of the casting. Protrusion 536
Has a diameter that is gradually reduced toward the tip and is drafted.

The cavity surface 530 of the hollow cylindrical portion 510
A collet 550 is fitted on the outer peripheral surface 544 on the opposite side. As shown in FIG. 7, the collet 550 is divided at equal angular intervals in the circumferential direction, and is formed into a plurality (preferably six or more) of the segments 551. The inner peripheral surface 554 of the collet 550 is pressed against the outer peripheral surface 544 of the hollow cylindrical portion 510 by mechanically changing (reducing the diameter of) the collet 550 by the collet diameter changing device 552. The hollow cylindrical portion 510 is contracted by elastic deformation. The outer peripheral surface of collet 550 is fixed
A tapered outer peripheral surface 556 whose diameter gradually increases toward the side is formed.

The collet diameter changing device 552 includes a taper member 560 and an axial moving device 564 for moving the taper member 560 in the axial direction. Taper member 560
Has a tapered inner peripheral surface 568 corresponding to the tapered outer peripheral surface 556, and a number of balls 570 are interposed between the tapered outer peripheral surface 556 and the tapered inner peripheral surface 568. ing. These balls 570
A retainer 572 independent of the tapered member 560 and the collet 550 is held at a fixed relative position to each other and rotatably individually. Each ball 570 is held so as to protrude from both the outer peripheral surface side and the inner peripheral surface side of the retainer 572, and forms a rolling bearing in cooperation with the retainer 572. Ball 570 is tapered outer peripheral surface 55
6 and the inner peripheral surface 568 of the taper,
The friction when the taper member 560 and the collet 550 are tightly fitted by the axial moving device 564 is reduced.
Restriction surfaces 576 and 578 integrally provided at two axially separated portions of the tapered member 560 prevent the rolling bearing from being pulled out from between the collet 550 and the tapered member 560. The axial movement device 564 includes:
A hydraulic cylinder (not shown) which is a type of hydraulic actuator as a drive source, and a connecting member 5 for connecting a piston rod 580 and a tapered member 560 of the hydraulic cylinder.
82.

An ejector device 590 is provided at a position in the movable mold 502 which does not interfere with other members. The ejector device 590 includes, similarly to the ejector device 260, an extrusion cylinder 592 fixed to the movable mold 502 and an extrusion member 596 having a plurality of extrusion pins 594. When the piston rod 598 is extended by driving the pushing cylinder 592, the pushing member 596 is pushed out, and the tip surface of the pushing pin 594 is moved to the cavity surface 532.
From the retracted end position, which defines the cavity 540 in conjunction with the front end, to an advanced end position that projects into the cavity 540 and extrudes the cast product.

The cavity 540 passes through the runner 600,
It is communicated with a sleeve 602 having a pouring port.
A gate 606 having a smaller cross-sectional area than other portions is formed at the end of the runner 600 on the cavity 540 side. In this embodiment, an injection device including a sleeve 602, a plunger 608, a plunger tip 610, a plunger driving device, and the like having the same configuration as the above embodiment is provided, but detailed illustration and description thereof are omitted.

After the movable mold 502 is brought close to the fixed mold 500 and the parting surfaces 504 and 506 are brought into close contact with each other, the axial moving device 564 is driven, and the tapered member 5 is moved.
60 is advanced so that its tapered inner peripheral surface 568 and the tapered outer peripheral surface 556 of the collet 550 are tightly fitted to each other, and the hollow cylindrical portion 510 and the portion adjacent to the hollow cylindrical portion 510 are elastically moved inward toward the inner side. The cavity surface 530, which is the inner peripheral surface, is deformed to reduce the diameter (see FIG. 6). The portion adjacent to the hollow cylindrical portion 510 is reduced in diameter along the tapered outer peripheral surface 524 of the fitting member 520, and the inner peripheral surface thereof is brought into close contact with the tapered outer peripheral surface 524 of the fitting member 520, so that the cavity 540 is formed. And axial moving device 564
The communication with the inside of the movable mold 502 provided with the above is interrupted. Metal (for example, aluminum alloy) is placed in the cavity 540 while the elastic deformation state of the hollow cylindrical portion 510 is maintained.
Of molten metal is injected. After the injected molten metal is solidified, the fixed mold 500 and the movable mold 502 are opened, and the casting is held by the movable mold 502 and separated from the fixed mold 500.
Thereafter, the taper member 560 is retracted, and the collet 5
By being separated from the outer peripheral surface 556 of the taper 50, the elastic deformation of the hollow cylindrical portion 510 is eliminated, and the diameter of the hollow cylindrical portion 510 is increased, so that the hollow cylindrical portion 510 is radially connected to the cavity surface 530 and the outer peripheral surface of the casting. Gaps occur. Therefore, the cast product held by the movable mold 502 is easily pushed away by the ejector device 590. The present casting mold apparatus is suitable, for example, for casting a material forming the head of a compressor piston.

In the present embodiment, the tapered member 560
And the collet 550 have a tapered surface, and the thickness of the hollow cylindrical portion 510 may be constant over the entire length. Therefore, it is easy to uniformly reduce the diameter of the entire hollow cylindrical portion 510. Further, since the tight fitting between the taper member 560 and the collet 550 is performed through the rolling bearing, the frictional resistance can be reduced, and the operating force of the axial moving device 564 can effectively reduce the diameter of the hollow cylindrical portion 510. This makes it possible to reduce the size of the axial movement device 564. Further, the taper member 5
Compared with a case where the collet 550 and the collet 550 are directly tightly fitted with each other, an effect of reducing abrasion and improving durability can be obtained.

In order to elastically deform the hollow cylindrical portion 510 while maintaining its roundness as much as possible, it is desirable to increase the number of segments, and to minimize the gap between the segments in the reduced diameter state. It is desirable to do so. In addition, it is desirable that the gap between the segments is uniform in the expanded state. For this reason, for example, similar to a normal collet, the segments are not completely separated from each other and are elastically deformable at one end in the axial direction. The parts can be connected to each other. This connecting portion is desirably disposed at a portion separated in the axial direction from the hollow cylindrical portion 510, that is, a portion close to the movable body 511 side.

As is clear from the above description, the present embodiment is a case where the peripheral surface constituting the cavity surface is the inner peripheral surface, and the hollow cylindrical portion 510 is an example of the hollow cylindrical portion. The tapered outer peripheral surface 556 of the collet 550 is a first tapered surface whose diameter linearly changes in the axial direction, and the tapered inner peripheral surface 568 of the tapered member 560 is a second tapered surface corresponding to the first tapered surface. . The collet 550 and the collet diameter changing device 552 constitute an elastic deformation device. The collet 550 is an example of a reduction member that contacts the outer peripheral surface of the hollow cylindrical portion 510, and the collet diameter changing device 5
52 is the outer peripheral surface 5 of the hollow cylindrical portion 510
44 to the hollow cylindrical portion 510.
Of the pressing device. A collet and a collet diameter changing device that mechanically changes the diameter of the collet as in the present embodiment are manufactured by using a form in which a peripheral surface that forms a cavity surface is an outer peripheral surface (for example, the embodiment shown in FIGS. Embodiment 5 shown in FIG. 5).

The casting mold apparatus and the casting method using the same according to the present embodiment are a molded product made of a material mainly composed of aluminum, for example, the above-described cylinder bore 12.
Although it is suitable for molding of the front housing 10 and the like, the casting mold apparatus of the present invention and the casting method using the same can be applied to the manufacture of other parts.

Although some embodiments of the present invention have been described in detail above, these are merely examples, and the present invention is described in the above section [Problems to be solved by the invention, means for solving problems and effects]. The present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art, including the described embodiment.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a swash plate type compressor manufactured using a casting mold apparatus according to an embodiment of the present invention and manufactured by a casting method according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a cylinder block of the swash plate type compressor.

FIG. 3 is a front view (partially sectional view) schematically showing a casting apparatus provided with the casting mold apparatus.

FIG. 4 is a front sectional view showing a main part of the casting mold apparatus.

FIG. 5 is a front sectional view showing a casting mold apparatus according to another embodiment of the present invention.

FIG. 6 is a front sectional view showing a casting mold apparatus according to still another embodiment of the present invention.

FIG. 7 is a side sectional view showing a part of the casting mold apparatus.

[Explanation of symbols]

10: Cylinder block 12: Cylinder bore 16:
Front housing 214: Opening / closing cylinder 22
4: fixed type 226: movable type 236: cavity 240, 242: cavity surface 250: sleeve 2
60: Ejector device 280: Hollow cylindrical portion 284: Fitting hole 300: Cavity surface 304: Tapered inner peripheral surface 310: Tapered member 326: Tapered outer peripheral surface 400: Fixed type 402: Movable type 410: Hollow cylindrical portion 412: Fitting hole 420: cavity surface 422, 424: cavity surface 426: cavity 428: tapered inner peripheral surface 4
40: tapered member 444: tapered outer peripheral surface 500: fixed type 502: movable type 510: hollow cylindrical portion 52
4: taper outer peripheral surface 530, 532: cavity surface 5
38: cavity surface 540: cavity 550: collet 552: collet diameter changing device 556: taper outer peripheral surface 560: taper member 564: axial moving device 568: taper inner peripheral surface 570: ball 590: ejector device

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) B22D 17/22 B22D 17/22 FH CK (72) Inventor Masaki Ota 2-chome Toyotamachi, Kariya City, Aichi Prefecture No. 1 Inside Toyota Industries Corporation (72) Inventor Yoshio Fujita 2-1-1 Toyota-cho, Kariya City, Aichi Prefecture Inside 1-2 Toyota Motor Loom Works (72) Inventor Osamu Hiramatsu 2-Toyota Town, Kariya City, Aichi Prefecture No. 1 Toyoda Automatic Loom Works, Ltd. (72) Inventor Yoshiharu Yoshida 8 Kyowacho Chaya, Obu City, Aichi Prefecture Toyota Sulzer Co., Ltd. F-term (reference) 4E093 NB01 QA04 QB01 QB07 QD01 UC01 UC02

Claims (6)

[Claims] 1. A method for casting a casting having at least one of an inner peripheral surface and an outer peripheral surface, comprising: forming a hollow cylindrical portion having a cavity surface for molding at least one of the inner peripheral surface and the outer peripheral surface. The mold provided is closed, and a cavity having a shape corresponding to the casting is formed inside the mold, and the hollow cylindrical portion is displaced with one of the inner peripheral surface and the outer peripheral surface toward the cavity. Elastic deformation in the direction to be performed, injecting a metal melt into the cavity while maintaining the elastic deformation state, after the melt solidifies, open the mold and eliminate the elastic deformation of the hollow cylindrical portion, A casting method, wherein a casting is removed from a mold. 2. The cylinder according to claim 1, wherein the cast product is a cylinder block having a plurality of cylinder bores of a swash plate compressor, and at least one of the inner peripheral surface and the outer peripheral surface is an inner peripheral surface of the cylinder bore. The casting method described. 3. The cast product is a front housing having a hollow cylindrical portion of a swash plate type compressor, and at least one of the inner peripheral surface and the outer peripheral surface is an inner peripheral surface of the hollow cylindrical portion. 2. The casting method according to 1. 4. A mold apparatus for casting a casting having at least one of an inner peripheral surface and an outer peripheral surface, the hollow cylinder having a cavity surface for molding one of the inner peripheral surface and the outer peripheral surface. A mold having a cylindrical portion; and an elastic deformation device for elastically deforming the hollow cylindrical portion of the mold in a direction to displace one of the inner peripheral surface and the outer peripheral surface of the hollow cylindrical portion toward the cavity. A casting mold apparatus comprising: 5. The hollow cylindrical portion is formed of a member separate from the main body of the mold, and at least a portion adjacent to a portion functioning as the hollow cylindrical portion is formed on the main body. The casting mold apparatus according to claim 4, wherein the fitting is performed while leaving a gap in the radial direction with the joining portion. 6. A surface of the hollow cylindrical portion opposite to a cavity surface forming one of the inner peripheral surface and the outer peripheral surface has a dimension gradually increasing in a direction parallel to a center axis of the hollow cylindrical portion. A taper member having a taper surface corresponding to the taper surface is provided while the taper surface is changed, and the elastic deformation device is configured to attach the taper member and the taper member to the taper surface of the hollow cylindrical portion. The casting mold apparatus according to claim 4 or 5, further comprising a tight fitting device for tight fitting.