JPH04339556A - Device for holding cylindrical insert - Google Patents

Abstract

PURPOSE:To provide a cylindrical insert, by which charging and holding of the insert into an insert holding part are facilitated and damage of a collapsible core can be eliminated. CONSTITUTION:A spiral groove 14b is arranged on outer peripheral face of a mandrel 14 (the insert holding part) and a coil spring 19 is charged into this groove 14b. This coil spring 19 is formed with small diameter part 19b at end part and large diameter part 19c followed to this. Further, one end of the coil spring 19 is fixed to the mandrel 14 and the other end is made to non-fixing.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applied to a mold casting apparatus for casting engine blocks of automobiles, etc., in which a cylindrical insert such as a cylinder liner is inserted into an insert holder on the mold side and held. The present invention relates to a shaped insert holding device.

0002

[Prior Art] Generally, when a cylinder block for an engine such as an automobile is cast in a mold using aluminum or the like, a cast iron cylindrical insert serving as a cylinder liner is loaded into the mold of a casting device, and then this cylinder Aluminum is cast so that the shaped insert and the aluminum casting part are integrated.

FIG. 6 is a vertical cross-sectional view of a main part of a conventional mold casting apparatus equipped with a holding device for holding this type of cylindrical insert, and FIG. 7 is an enlarged vertical cross-sectional view of the cylindrical insert charging section. A lower mold 1, only a part of which is shown, is fixed on a fixed platen (not shown), and above this lower mold 1 is supported by a movable platen (not shown), and a movable platen is mounted by a mold clamping cylinder. An upper mold 2 that moves up and down at the same time is disposed. Between these lower mold 1 and upper mold 2, for example, 2
A plurality of slide cores 3 which are divided and opened and closed by moving in the radial horizontal direction by opening and closing cylinders are supported and provided on the lower mold 1 side. A cylindrical mandrel 4 is suspended from the center of the upper mold 2, and the lower end of the inner hole of the mandrel 4 fits into the convex portion 1a at the center of the lower mold 1 during mold clamping. is configured to be and,
In the area surrounded by the clamped upper and lower molds 2, 1, the closed slide core 3, and the mandrel 4, a cylindrical cylinder equivalent part 5a and a semicylindrical cylinder case equivalent part 5b are formed. In addition, a collapsible sand core 6 formed in a substantially cylindrical shape is supported and installed on the upper mold 2 side in the cavity 5 when the mold is clamped. There is.

The positioning pin 7 inserted and fixed into the pin hole 2a of the upper mold 2 and protruding downward is fitted into the inner hole 4a of the mandrel 4, and also fits into the outer peripheral surface 4 of the mandrel 4.
A cylindrical cylinder liner 8 inserted during molding is fitted into b. A partially cut-out ring is formed between the mandrel 4 and the positioning pin 7 and engages with the ring groove 4c of the mandrel 4 to restrict movement of the positioning pin 7 relative to the mandrel 4 in the axial direction. A retaining ring 9 is loaded with an expanded force. Further, as shown in an enlarged view in FIG. 7, between the mandrel 4 and the cylinder liner 8, there is formed a ring shape with a part cut out, which engages with the ring groove 4d of the mandrel 4, and the cylinder liner with respect to the mandrel 4. A retaining ring 10, which restricts the axial movement of the liner 8, is loaded with an expanded force.

With this structure, when the upper mold 2 is opened and the slide mold 3 is opened, the cylinder liner 8 is placed on the mandrel 4 holding the sand core 6.
After fitting the mandrel 4 to the positioning pin 7 and supporting it, the slide mold 3 is closed by the opening/closing cylinder, and the upper mold 2 is lowered and clamped by the mold clamping cylinder. The inner hole 4a of the mandrel 4 hanging down from the mold 2 is fitted into the convex portion 1a of the lower mold 1. and,
When the molten metal is injected into the cavity 5, this molten metal is injected into the crankcase equivalent part 5b and the cylinder equivalent part 5a outside the cylinder liner 8 except for the sand core 6, and the cylinder liner 8 is inserted. It is cast in the same condition. After the molten metal is solidified, when the upper mold 2 and the slide mold 3 are opened and the extrusion pin is projected, the solidified product, ie, the engine block, is extruded from the cavity 5 and taken out of the upper mold 2. Thereafter, when the sand core 6 left in the engine block, which is a cast product, is collapsed, the sand core 6 is taken out in pieces to form a cooling water circulation jacket as a space.

[0006]

However, in such a conventional cylindrical insert holding device, an expansion force is applied to the retaining ring 10 in order to restrict the movement of the mandrel 4 and the cylinder liner 8 in the axial direction. The ring groove 4d in which the retaining ring 10 is inserted
is formed deeper than its cross-sectional diameter so that the retaining ring 10 is retracted when it is inserted into the mandrel 4, so that the retaining ring 10 is concentric with the mandrel 4 as shown by the chain line in FIG. If you try to insert the cylinder liner 8 into the mandrel 4 in this state, the cylinder liner 8 will be stopped by the retaining ring 10 and will not be inserted. There is. In addition, even if it does enter, the collapsible sand core 6 may be damaged due to the shock when it is inserted, and at this time, the molten metal may enter the cracks formed in the sand core 6, resulting in the cast product having the desired shape. There is a problem in that not only is it not possible to obtain sand, but also that the sand remaining in the cavity 5 after casting cannot be sufficiently removed.

The present invention was made in view of the above points, and provides a cylindrical insert holding device that facilitates fitting of a mandrel and a cylinder liner and eliminates damage to a collapsible sand core. It is intended to.

[0008]

[Means for Solving the Problems] In order to achieve such an object, the present invention provides a plurality of consecutive pitches of spiral grooves in the axial direction on the outer peripheral surface of a cylindrical or cylindrical insert holding portion. A coil spring with multiple turns is inserted into this spiral groove, and the end of this coil spring on the insert insertion side is held by a part of the insert holding part so that it does not move, and this coil spring is The outer diameter of the coil spring is smaller than the diameter of the outer peripheral surface of the groove of the insert holding part up to at least 2/3 pitch from the end of the coil spring on the insert insertion side, and the outer diameter of the remaining part following this small diameter part is diameter,
It was made slightly larger than the outer diameter of the insert holding part.

[0009]

[Operation] A coil spring is inserted into the helical groove provided on the outer circumferential surface of the insert holding part, and a cylindrical insert is further inserted on top of it. Since the side is formed with a small diameter, it is easy to insert the cylindrical insert, and since the large diameter part of the coil spring expands after insertion, the cylindrical insert can be moved axially relative to the insert holding part. movement is regulated and fixed.

0010

[Embodiment] Figures 1 to 5 show an example in which a cylindrical insert holding device according to the present invention is implemented in a vertical mold die casting machine.
is a front view of the mandrel as an insert holding part, Figure 3
4 is a plan view of the coil spring, FIG. 4 is a longitudinal sectional view, and FIG. 5 is an enlarged longitudinal sectional view of the cylindrical insert insertion part. In the figure, a lower mold 11, only a part of which is shown, is fixed on a fixed plate (not shown) fixed to the machine base, and above this lower mold 11 is supported by a movable plate (not shown). The upper mold 1 moves up and down with the movable platen using the mold clamping cylinder.
2 are arranged. Between the lower mold 11 and the upper mold 12, a plurality of slide cores 13, which are divided into two parts in the circumferential direction and are moved in the radial horizontal direction by opening/closing cylinders to open and close, are supported on the lower mold 11 side. It is well established.

A cylindrical mandrel 14 is suspended from the center of the upper mold 12 with its base fixed to the upper mold 12, and the lower end of the inner hole 14a of the mandrel 14 is
It is configured to fit into a convex portion 11a at the center of the lower mold 11 during mold clamping. In the area surrounded by the clamped upper and lower molds 12, 11, the closed slide core 13, and the mandrel 14, there is a cylindrical cylinder equivalent part 15a and a semicylindrical cylinder case equivalent part 15.
A cavity 15 consisting of b is formed, and
In the cavity 15 during mold clamping, a collapsible sand core 16 formed in a substantially cylindrical shape is suspended with its base supported by the upper mold 12 side. Further, a positioning pin 17 inserted and fixed into a pin hole 12a of the upper mold 12 and protruding downward is fitted into an inner hole 14a of the mandrel 14, and the center of this positioning pin 17 has the convex Part 11
An air passage 17a is provided to communicate a vacuum device (not shown) with the cavity 15 via a space 18 above the cavity 17a.

[0012] On the outer peripheral surface of the mandrel 14, a plurality of spiral grooves 14b are continuously provided in the axial direction at a plurality of pitches. Furthermore, a cylinder liner 20 as a cylindrical insert inserted during casting is inserted into the outer peripheral surface of the mandrel 14. In the case of this embodiment, the end 14c of the groove 14b on the side where the coil spring 19 is inserted is extended to the open end 14d of the mandrel 14, and after the coil spring 19 is inserted, the extension of the groove 14b is is filled in so as not to create a gap. Further, one end of the coil spring 19 is fixed by inserting a bent piece 19a formed at the end on the side where the cylinder liner 20 is inserted into the hole 14e on the mandrel 14 side, and the other end of the coil spring 19 is fixed. It is not fixed and has a free end. Furthermore, the end 1 of the groove 14b on the free end side of the coil spring 19
4f is the coil spring 1 in consideration of the expansion of the coil spring 19.
It is extended to be longer than the free end of 9. In this device, the outer diameter of the coil spring 19 is a small diameter portion 19b that is smaller than the diameter of the outer circumferential surface of the groove 14b of the mandrel 14 up to at least ⅔ pitch from the end on the side where the cylinder liner 20 is inserted. The outer diameter of the remaining portion following this small diameter portion 19b is formed to be slightly larger than the outer diameter of the mandrel 14. Note that in this embodiment, the coil spring 19
Although the end portion on the side opposite to the small diameter portion 19b also has a small diameter, it is not necessarily necessary to make the diameter small.

The casting operation of the die casting machine equipped with the above-mentioned cylindrical insert holding device will be explained. Upper mold 1
2 is opened and the slide mold 13 is opened, and the coil spring 19 is inserted into the groove 14b of the mandrel 1.
4 to support the sand core 16, and after this mandrel 14 is fitted and supported by the positioning pin 17, a cylinder liner 20 as a cylindrical insert is inserted onto the outer peripheral surface of the mandrel 14 via a coil spring 19. do. During this charging, as shown in FIG.
Since the large diameter portion 19c is in contact with the bottom surface of the groove 14a, and the large diameter portion 19c is spaced apart from the bottom surface of the groove 14a so that its outer periphery only slightly protrudes from the groove 14a, the cylinder liner 20 can be easily inserted. That is, in the conventional example shown in FIG. 7, the angle indicated by the symbol θ in the figure is much smaller than 45°, so the retaining ring 10 does not retract into the groove 4d, but in FIG. 5, this angle θ is 45° or more. Therefore, as the cylinder liner 20 moves forward, the large diameter portion 19c of the coil spring 19 easily retracts into the groove 14a. After this, cylinder liner 2
When the cylinder liner 20 is inserted deeper than the position shown in FIG. .

After this, the slide mold 13 is closed by the opening/closing cylinder, and the upper mold 12 is lowered and clamped by the mold clamping cylinder. When the plunger tip pushes the molten metal 8 in the injection sleeve (not shown), the molten metal 8 is injected into the cavity 15. In this case, the molten metal 8 is injected into the cavity 5b corresponding to the crankcase and into the cavity 5a outside the cylinder liner 20, excluding the sand core 16, and is cast with the cylinder liner 20 inserted. It will be done. When the molten metal in the cavity 15 solidifies and cools, the movable platen is raised together with the upper mold 12 by the mold clamping cylinder, but in this case, the slide mold 13 supported by the upper mold 12 is also solidified by the molten metal. As the product rises. After opening the slide mold 13, a piston is lowered using an extrusion cylinder (not shown), and the product is extruded. After the extruded product is taken out of the machine, the mandrel 14 is removed and the sand core 16 is collapsed by vibration etc., and when it is taken out as sand, it has a jacket for cooling water circulation and a cylinder liner. An engine block with No. 16 inserted is obtained.

Although this embodiment shows an example in which the present invention is applied to a vertical type die-casting machine, it can also be applied to a horizontal type die-casting machine, and the effect is even more remarkable. . That is, in the case of a horizontal clamping mold, as is clear from rotating 90 degrees of FIG.
Since the cylinder liner 8 protrudes greatly from the mandrel 4, it is impossible to insert the cylinder liner 8 into the mandrel 4. However, in this explanation, there is no need to worry about this, and the effect is greater than that of the conventional method. Further, in this embodiment, an example was shown in which the cylinder liner serving as the insert holding portion was formed into a cylindrical shape, but it may also be formed into a cylindrical shape, and the same effect can be obtained.

[0016]

Effects of the Invention As is clear from the above description, in the cylindrical insert holding device according to the present invention, spiral grooves are formed continuously at multiple pitches in the axial direction on the outer circumferential surface of the cylindrical or cylindrical insert holding part. A coil spring with multiple turns is inserted into this spiral groove, and the end of the coil spring on the insert insertion side is held by a part of the insert holding portion so as not to move. The outer diameter of the coil spring is a small diameter part that is smaller than the diameter of the outer peripheral surface of the groove of the insert holding part up to at least 2/3 pitch from the end of the coil spring on the insert insertion side, and the remaining part following this small diameter part. By making the outer diameter of the cylindrical insert slightly larger than the outer diameter of the insert holding part, when inserting the cylindrical insert into the insert holding part, the coil spring does not interfere with the insertion, and the insert can be easily inserted. , the cylindrical insert can be used to securely hold the material, improving workability. Furthermore, since the sand core is not damaged during charging and the sand left inside the product can be sufficiently removed, a product with a desired shape can be obtained and the quality of the product can be improved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a cylindrical insert holding device.

FIG. 2 is a front view of a mandrel as an insert holding part.

FIG. 3 is a plan view of a coil spring.

FIG. 4 is a longitudinal cross-sectional view of a coil spring.

FIG. 5 is an enlarged longitudinal cross-sectional view of the cylindrical insert insertion part.

FIG. 6 is a longitudinal cross-sectional view of a conventional cylindrical insert holding device.

FIG. 7 is an enlarged vertical cross-sectional view of a cylindrical insert insertion portion in a conventional cylindrical insert holding device.

[Explanation of symbols]

14 Mandrel 14b Groove 15 Cavity 16 Sand core 19 Coil spring 19a　Folded piece 19b Small diameter part 19c Large diameter part 20 Cylinder liner

Claims (1)

[Claims] [Claim 1] A spiral groove is provided continuously at multiple pitches in the axial direction on the outer peripheral surface of a columnar or cylindrical insert holding part, and a coil spring with multiple turns is inserted into the spiral groove. The end of the coil spring on the insert insertion side of the lever is held by a part of the insert holding portion so as not to move, and the outer diameter of the coil spring is at least 2 mm from the end of the coil spring on the insert insertion side. /3 pitch is characterized by a small diameter part that is smaller than the diameter of the outer peripheral surface of the groove of the insert holding part, and the outer diameter of the remaining part following this small diameter part is slightly larger than the outer diameter of the insert holding part. A cylindrical insert holding device.