JPH0579426B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a casting mold for forming a cast product such as a multi-pot caliper for a disc brake, in which cylinder holes for piston insertion are arranged in parallel, The present invention relates to a casting mold structure that forms a communication hole that communicates adjacent cylinder holes during molding of a cast product.

[Conventional technology]

Among cast products with cylinder holes arranged side by side on one side, for example, each piston inserted into a pair of cylinder holes is advanced by pressure fluid and pressed against one side of a disc rotor that rotates together with the wheel for braking action. In a two-pot type caliper for a disc brake, a communication hole is provided in the partition wall between the cylinder holes to communicate the two cylinder holes and allow hydraulic fluid to flow between them.

This communication hole may be formed by a metal pipe, shell mold, green sand mold, or other sand core during casting, or may be formed by post-processing after casting, for example by drilling from the side of the cylinder hole. It is formed by penetrating the partition wall.

[Problem that the invention seeks to solve]

However, with metal pipes,
Because the materials and hardness of the pipe and the casting base material are different, the inner diameter is easily damaged during processing, the pipe requires several castings, burrs are likely to form, and a deburring process is required. It is easy to produce defects, requires several core castings, requires a sand removal process, and for post-processing, processing equipment is required, and a stopper such as a blind plug is required to close the opening liquid-tight. Common problems were that the casting cycle took a long time.

Therefore, the present invention aims to solve the above-mentioned problems. Communicating holes can be formed at the same time as casting, mold division is easy, there is no post-processing for communicating holes, and high-quality cast products can be provided at low cost. The purpose is to provide casting molds.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a casting mold for a cast product in which a plurality of cylinder holes are arranged in parallel, in which the cylinder holes are formed in either a fixed mold or a movable mold of the casting mold. To form a cast hole that protrudes from one of the mold parts of the child, etc. into a partition wall space forming a partition between adjacent cylinder holes, and serves as a communication hole that communicates both cylinder holes in the partition. A cast-out pin is rotatably provided, and the cast-out pin is formed in an arc shape centered on a rotation fulcrum, and at least a portion protruding into the partition wall space is formed to have the same cross-section or a tapered shape. It is characterized by the fact that

[Effect]

The cast-out pin that forms the cast-out hole is rotated about the pivot shaft in conjunction with the joining operation of the fixed mold and the movable mold, or before or after the two molds are joined, so that the tip of the cast-out pin forms the cylinder hole. After one of the mold parts, such as a forming core, is arranged to protrude into the partition wall space, molten metal is injected into the cavity formed by joining both molds, thereby molding the cast product.

The cast hole formed at the same time as the above molding may be opened to the adjacent cylinder hole and used as a communicating hole, or a thin partition wall may be left between the tip of the cast pin and the adjacent cylinder hole to form a cylinder. The communication may be established by machining a cylinder hole by cutting the inside of the hole to a large diameter, and in either case,
Post-processing for forming communicating holes is not required.

After molding, the casting pin is rotated about the pivot shaft in conjunction with the mold splitting operation of the fixed mold and movable mold, or by operation by another drive source before or after mold splitting. After being pulled back into the mold section, the cast product is released from the mold.

〔Example〕

A first embodiment in which the present invention is applied to a casting mold for molding a two-pot caliper for a disc brake will be described below with reference to FIGS. 1 to 3.

The casting mold 1 includes a fixed mold 3 fixed to a base plate 2,
A movable mold 4 that is moved forward or backward by a cylinder device (not shown) to join or separate from the fixed mold 3;
A cast pin operating mechanism 5 disposed within the movable mold 4
and a pair of cores 6 and 7.

A guide pin 9 for guiding the movement of the slider 8 of the casting pin actuating mechanism 5 is attached to the fixed mold 3 in an oblique direction, and a bridge member 10 having a guide surface 10a having the same slope as the pin 9 is attached to the bolt 11. Each is protruded.

The movable mold 4 includes a front mold 4a that forms a cavity 12 by joining with the fixed mold 3, a middle mold 4b that is connected to the front mold 4a with a bolt 13, and a spacer 14 interposed in the middle mold 4b and a bolt 15. and a rear mold 4c that is connected to the rear mold 4c.

A press plate 17 is disposed in a space between the middle mold 4b and the rear mold 4c surrounded by the spacer 14. A support pin 16 and a protruding pin 18 for releasing the caliper are protruded from the press plate 17.
7 is supported by inserting a support pin 16 into the front mold 4a and the middle mold 4b, and has an ejecting pin 18 inserted through the front mold 4a and the middle mold 4b so that its tip faces the cavity 12. . The movable mold 4 has a positioning pin 20 inserted into the guide hole 19 of the fixed mold 3.
You will be guided to move forward and backward.

The cores 6 and 7 are installed in the front mold 4a of the movable mold 4, and are provided with the molding parts 6a and 7a on the tip side protruding from the front part of the front mold 4a.
Reference characters a and 7a correspond to mold parts of the present invention, which protrude into the cavity 12 when the molds 3 and 4 are joined to form a pair of cylinder holes 22a and 22b of the caliper 21.

Further, the casting pin operating mechanism 5 has a swing arm 2 attached to a gate-shaped support frame 23 attached to the core 6 within the front mold 4a.
4 is pivotally supported by a rotation support shaft 25, and the arm portion 2 of the swing arm 24 is further disposed within the guide groove 26 of the medium-sized 4b.
4a, a cast-out pin 27 is pivotally supported by a support shaft 28, and the swing arm 24 and cast-out pin 27 are rotated by the slider 8 moving within the guide groove 26 of the medium 4b. .

The cast-out pin 27 has a base 27a pivoted on the swing arm 24, and a pin 27b, which is tapered and curved in an arc centered on a pivot shaft 25 serving as a pivot point, on one side. It is inserted into a sliding hole 29 formed in the core 7 of.

Also, the slider 8 moving within the guide groove 26
In the slide block 8b, which has a through hole 8a through which the guide pin 9 is inserted, support pieces 8c, 8c projecting in a bifurcated manner toward the bottom side of the guide groove 26 are pivotally supported by a support shaft 28. Swing arm 24 and cast pin 27
It is extended to sandwich the . Each support piece 8c
8 d of inclined holes into which both ends of the support shaft 28 are loosely fitted are formed in the same phase, so that the support shaft 28 can move along the inclined holes 8 d.

The slider 8 moves within the guide groove 26 under the guidance of the guide pin 9 and the bridge member 10 as the movable mold 4 advances and retreats, and when the fixed mold 3 and the movable mold 4 shown in FIG. That is, during caliper molding, the support shaft 28 is inserted into the slide block 8 of the inclined hole 8d.
Move it to the end on the b side.

As a result, the tip 27c of the pin 27b of the cast-out pin 27 protrudes from the sliding hole 29 of the core 7, and the partition wall forming space of the cavity 12 that forms the partition wall 30 between both cylinder holes 22a and 22b of the caliper 21 is formed. 12a and adjacent cylinder hole 22.
It reaches the molding part 6a of the core 6 which forms a. At least the tip 27c of the cast pin 27 that projects into the partition wall space is formed to have the same or tapered cross section. Reference numeral 31 denotes a cylinder for releasing the caliper 21 formed from the movable mold 4. Shows the rod of the device.

Next, the operation of this embodiment configured as described above will be explained.

The fixed mold 3 and the movable mold 4 are in the joint position shown in FIG. rotates and pin 27b
The tip end 27c of the core 6 protrudes to a position reaching the molded portion 6a of the core 6 which is protruded into the cavity 12 as described above.

After the molten metal is injected into the cavity 12 and solidified, the movable mold 4 is moved back to the position shown in FIG. 2 using a cylinder device to split the mold.

At this time, as the movable die 4 retreats, the slider 8 moves toward the opening of the guide groove 26 while sliding on the guide surface 10a of the bridge member 10 under the guidance of the guide pin 9, and is loosely fitted into the inclined hole 8d. The supporting shaft 28 is moved to the bottom side of the guide groove 26.

As a result, the swing arm 24 and the core pin 27 rotate counterclockwise in FIG.
7c is pulled back into the sliding hole 29 of the core 7.

Further, as the movable mold 4 retreats, the releasing rod 31 moves forward toward the fixed mold 3, pushes the pressing plate 17, and causes the ejecting pins 18 of the plate 17 to protrude from the front mold 4a. , the caliper 21 is released from the mold.

The released caliper 21 has a cylinder hole 22.
A cast hole 32 is formed in the partition wall 30 together with the cylinder holes 22a and 22b, and since the cast hole 32 communicates with both the cylinder holes 22a and 22b, it can be used as a communication hole as is.

In this embodiment, the swinging arm 24 and the casting pin 27 of the casting pin operating mechanism 5 are operated by a slider 8, and the slider 8 can be moved as the movable mold 4 moves forward or backward. Therefore, there is no need to use a separate actuating device for the cast hole, the structure is simple, and the caliper, which is a cast product, can be provided at low cost.

Note that when casting is repeated, burrs and the like may adhere to the inside of the cavity of the casting mold, making it difficult to perform the casting smoothly, so maintenance is usually performed every predetermined number of castings. This maintenance involves disassembling the casting mold, removing burrs, etc. by heating or other means, applying a mold release agent inside the cavity, and reassembling it.
For example, maintenance is performed every 60 castings, and at this time, a release agent is also applied to the cast pin 27.

Therefore, the cast-out pin 27 must be removed for each maintenance.
The cast-out pin 27 is curved in an arc shape centered on the pivot shaft 25 serving as a pivot point, and the cast-out pin 27 is coated with a mold release agent at least in the partition wall space. The protruding tip 27c is formed to have the same cross-sectional shape or a tapered shape, and as the movable die 4 advances and retreats, the slider 8 is guided by the guide pin 9 and the piece member 10 into the guide groove 26. By moving the pivot 28 of the swing arm 24 along the inclined hole 8d of the slider 8 and rotating the swing arm 24 about the pivot shaft 25, the swing arm 24 is rotated about the pivot shaft 25. 24 is forcibly moved mechanically to cause the tip 27c of the cast pin 27 to appear and disappear into the partition wall forming space 12a of the cavity 12, which prevents shrinkage of the cast product. Therefore, the cast pin 27 will not become stuck.

4 to 6 show a second embodiment of the present invention, a casting mold 40 includes a fixed mold 43 supported on a base plate 41 by bolts 42, a front mold 44a, a middle mold 44b,
A movable mold 44 consisting of a rear mold 44c, and the movable mold 4
4, and a pair of cores 6 and 7.

The cast-out pin operating mechanism 45 includes a support frame 23
A swing arm 24 and a cast-out pin 27, which are pivotally supported by There is.

The casting pin 27 joins the fixed mold 43 and the movable mold 44, and when the swinging arm 24 abuts against the rear surface of the front mold 44a, the tip 27c of the pin 27b is inserted into the sliding hole 29 of the core 7. The tip 27c protrudes into the partition wall forming space 12a of the cavity 12 that forms the partition wall 30 between the cylinder holes 22a and 22b, and stops at a position where the partition wall 30 is slightly left between the adjacent cylinder holes 22a. It is set up like this.

The torque rods 46a, 46b are fixed type 4
The torque rod 46a on the fixed mold 43 side, which is divided by the mold dividing surface 47 of the movable mold 44 and the torque rod 46a on the fixed mold 43 side, which is supported by the torque plate 48,
6b and move the swinging arm 2 to the solid line position in FIG.
4 and the cast-out pin 27 are rotated to the imaginary line position.

When the fixed mold 43 and the movable mold 44 are joined, the molded parts 6a, 7a of the cores 6, 7 and the cast pin 27 are in the solid line position in FIG. The caliper 21 is then molded.

After molding the caliper, before the molds 43 and 44 are separated, the operating mechanism 49 for the casting pin is inserted into the fixed mold 4.
The rod 49a of the mechanism 49 connects the torque rods 46a and 46b via the torque plate 48.
, rotate the swinging arm 24 and cast pin 27 to the imaginary line position, pull the tip 27c of the pin 27b back into the sliding hole 29 of the core 7, and then move the movable mold 44. By retreating and using the mold release rod 31,
The caliper 21 is released from the front mold 44a.

The swinging arm 24, which retreats together with the movable mold 44,
The tip 27c of the cast pin 27 returns to its original position where it is pulled back into the sliding hole 29 of the core 7 by coming into contact with the return plate 50 shown by imaginary lines in the figure.

Caliper 2 molded with the casting mold 40 of this embodiment
1, the cast hole 51 does not penetrate into the cylinder hole 22a, but communicates with the cylinder hole 22a, 22b by cutting the inside of the cylinder hole 22a, 22b to a large diameter after molding to form a communication hole. No special post-processing is required.

FIG. 7 shows a third embodiment showing a modification of the cast-out pin operating mechanism, in which a pair of swinging arms 60, 60 each having a cast-out pin 61 pivotally supported on each arm portion 60a are pivoted around a pivot shaft 62. The cast-out hole that supports the cast-out pin 61 and serves as a communication hole is formed through the butt of the cast-out pin 61 by abutting the ends of the cast-out pin 61, and the swing arm 60 and the cast-out pin 6 after molding are connected to each other.
1 is pulled back by the pushing motion of the torque rod 63.

In the present invention, the cast pin may be formed integrally with the swing arm. Further, in the present invention, the movable type in each of the above embodiments can be replaced with a fixed type, and the fixed type can be replaced with a movable type.

In addition, in each of the above embodiments, the caliper was described as a two-pot type, but the casting mold of the present invention can form a caliper with three or more cylinder holes by combining a plurality of cast-out pins. Communication holes can also be formed, and the method can be widely applied to the molding of other cast products that require communication holes.

〔Effect of the invention〕

As described above, in the casting mold of the present invention, a partition between adjacent cylinder holes is formed from one of the mold parts such as a core forming a cylinder hole in either the fixed mold or the movable mold. A cast-out pin is rotatably provided to protrude into the partition wall space and form a cast-out hole that becomes a communication hole that communicates both cylinder holes in the partition wall, and the cast-out pin is rotated with a rotation fulcrum. Since the center is formed into an arc shape and at least the part protruding into the partition wall space is formed to have the same cross-sectional shape or a tapered shape, there is no post-processing for the communication hole, and various conventional processes can be omitted, resulting in a high quality product. We can provide cast products at low cost.

Furthermore, since no settings are required before molding, the casting cycle is shortened, and the molds can be easily divided, resulting in excellent operability and workability of casting operations.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, FIG. 1 is a sectional front view of a casting mold in a molding state, FIG. 2 is a sectional front view of a casting mold in a split state, and FIG. 3 is a sectional front view of a casting mold in a molding state. is a cross-sectional view of FIG. 1, FIGS. 4 to 6 show the second embodiment, FIG. 4 is a cross-sectional view of FIG. 5, and FIG. FIG. 6 is a cross-sectional view taken from FIG. 5, and FIG. 7 is a front view of a core pin operating mechanism showing a third embodiment. 1...Casting mold, 2...Bed plate, 3...Fixed mold, 4
...Movable type, 4a...Front type, 4b...Medium size, 4c
... Rear mold, 5 ... Casting pin operating mechanism, 6,7...
... Core, 6a, 7a... Molding part that becomes the mold part, 8...
...Slider, 8a...Through hole, 8b...Slide block, 8c...Support piece, 8d...Slanted hole into which both ends of support shaft 28 are fitted loosely, 9...Guide pin, 10...
...Block member, 10a... Guide surface, 12... Cavity, 18... Projection pin for caliper release, 21
...Caliper, 22a, 22b...Cylinder hole 2
4... Swinging arm, 24a... Arm portion, 26... Guide groove, 27... Cast-out pin, 29... Sliding hole, 30
. . . Partition wall of caliper 21, 32 . . . Casting hole serving as a communicating hole.

Claims (1)

[Claims] 1. In a casting mold for a cast product in which a plurality of cylinder holes are arranged in parallel, one of the fixed mold and the movable mold of the casting mold has an adjacent mold part such as a core forming the cylinder hole. A cast-out pin is rotatably provided to protrude into a partition wall space forming a partition wall between the cylinder holes and to form a cast-out hole serving as a communication hole communicating both cylinder holes in the partition wall, The casting mold is characterized in that the casting pin is formed in an arc shape centered on a rotational fulcrum, and at least a portion projecting into the partition wall space is formed to have the same shape or a tapered shape in cross section.