Positioning device for casting sand mold and sand mold

Abstract

The positioning device comprises a positioning pin sleeve and a positioning pin which are matched with each other, the positioning pin sleeve is installed on an upper template in a clearance fit mode and comprises an inner hole matched with the positioning pin, an exhaust hole is formed in the top end of the positioning pin sleeve, and a through hole is formed in the middle of the positioning pin sleeve. A fastening groove is formed in the outer peripheral surface; the lower half part of the positioning pin is mounted on the lower template, the upper half part of the positioning pin extends upwards to be matched with an inner hole of the positioning pin sleeve, the positioning pin comprises two head sections which are integrally formed and have inclination and a cylindrical middle section, and a longitudinal exhaust groove is further formed in the position, matched with the positioning pin sleeve, of the middle section of the positioning pin; the sand mold comprises the positioning device. By means of the mode, matching precision can be improved through positioning matching between metal, the defect of dislocation or serious box lifting caused by dislocation or deviation is avoided, and application of medium and large castings can be met.

Description

Technical Field

[0001] The utility model relates to the technical field of casting, in particular to a positioning device for casting a sand mold and the sand mold. Background Art

[0002] There are two main casting processes: machine molding and hand-made resin sand molding. In resin sand molding, the precise fit of the upper and lower mold plates is key to ensuring casting quality. This is usually achieved through concave and convex positioning to solve the problem of mold misalignment.

[0003] The combination of locating holes and locating pins is widely used in various mold applications, primarily for guiding and ensuring assembly accuracy. During the resin sand molding process, mold guidance and positioning are particularly important; any slight deviation can lead to quality issues in the casting.

[0004] Traditionally, the upper and lower mold plates in resin sand molding are positioned using metal pins inserted directly into the resin sand to achieve a mating fit. However, there is a significant difference in physical strength between the two parts: when the casting is large or the box is heavy, the resin sand is easily squeezed and cracked, causing the fit to fail.

[0005] Currently, most sand casting molds are positioned using metal locating pins that mate with the locating pin holes in the resin sand mold. This positioning method is widely used in small automated production lines and the manufacture of simple structural parts due to its simplicity, ease of manufacture, and minimal space restrictions.

[0006] However, for medium and large castings, simply matching metal locating pins with resin sand, or simply matching the concave and convex parts of resin sand, is far from enough:

[0007] On the one hand, when the box is heavy and the molding is completed, the metal positioning pins and the sand mold pin holes are easily squeezed or cracked, which makes it impossible to guide the sand properly and cause misalignment.

[0008] On the other hand, when the box weight is large, the amount of molten iron and the speed are too high after the boxes are closed. Due to the combination of sand and metal, there is a gap between the two and the difference in physical material strength may lift the upper and lower boxes, thereby causing misalignment. Utility Model Content

[0009] The main technical problem solved by the utility model is to provide a positioning device that cooperates with a metal positioning pin and a metal positioning pin sleeve and is applied to a sand mold. It can improve the matching accuracy by utilizing the positioning cooperation between metals and avoid misalignment or serious box lifting caused by dislocation or deviation.

[0010] In order to solve the above technical problems, a technical solution adopted by the present invention is to provide a positioning device for casting sand molds, comprising:

[0011] A positioning pin sleeve is installed on the upper mold plate through a clearance fit, and the positioning pin sleeve includes an inner hole that cooperates with the positioning pin, a vent hole is provided at the top of the positioning pin sleeve, a through hole is provided in the middle, and a fastening groove is provided on the outer peripheral surface;

[0012] The locating pin has its lower half mounted on the lower mold plate, and its upper half extends upward to cooperate with the inner hole of the locating pin sleeve. The locating pin includes two integrally formed head sections with an inclination and a cylindrical middle section. A longitudinal exhaust groove is also provided at the position where the middle section of the locating pin cooperates with the locating pin sleeve.

[0013] In a preferred embodiment of the present invention, the inner hole size of the positioning pin sleeve matches the size of the positioning pin, and positioning is achieved through clearance fit.

[0014] In a preferred embodiment of the present invention, the bottom of the inner hole of the locating pin sleeve is provided with a circle of chamfers for guiding the insertion of the locating pin.

[0015] In a preferred embodiment of the present invention, the exhaust hole at the top end of the positioning pin sleeve is a through hole, which passes through the positioning pin sleeve and is connected to the inner hole.

[0016] In a preferred embodiment of the present invention, at least four through holes are provided and are evenly distributed along the circumference of the middle portion of the positioning pin sleeve.

[0017] In a preferred embodiment of the present invention, at least three fastening grooves are provided and are distributed circumferentially and spaced apart along the outer circumference of the positioning pin sleeve.

[0018] In a preferred embodiment of the present invention, the middle position of the middle section of the positioning pin has a flange surrounding the middle section, and the flange forms an upper half and a lower half of the positioning pin.

[0019] In a preferred embodiment of the present invention, at least four exhaust grooves are provided and are evenly distributed along the circumference of the middle section of the positioning pin.

[0020] In order to solve the above technical problems, a technical solution adopted by the utility model is: to provide a sand mold, including: an upper molding sand box, a lower molding sand box, an upper mold plate cooperating with the upper molding sand box, a lower mold plate cooperating with the lower molding sand box, and a positioning device, through which the positioning device is used to complete the positioning and guiding of the upper molding sand box and the lower molding sand box.

[0021] The beneficial effects of the utility model are: by using the cooperation between the positioning pin sleeve and the positioning pin, and utilizing the positioning cooperation between metals, accurate positioning and guiding the box are completed, which greatly improves the matching accuracy; this positioning and guiding function can avoid product misshape or serious box lifting caused by dislocation or deviation, which helps to improve production efficiency and product quality, and has low production cost, strong flexibility, and can be recycled and reused, saving costs, and can meet the application of medium and large castings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. Among them:

[0023] Figure 1 This is a cross-sectional view of a preferred embodiment of a sand casting mold of the present invention;

[0024] Figure 2 This is a structural diagram of a preferred embodiment of a positioning pin sleeve of the present utility model;

[0025] Figure 3 This is a structural diagram of a preferred embodiment of a positioning pin of the present utility model;

[0026] Figure 4 This is a structural schematic diagram of a preferred embodiment of a positioning device for casting sand molds of the utility model;

[0027] The markings of the components in the accompanying drawings are as follows:

[0028] 1. Locating pin sleeve, 2. Through hole, 3. Parting surface, 4. Lower molding sand box, 5. Exhaust groove, 6. Exhaust hole, 7. Fastening groove, 8. Upper molding sand box, 9. Upper mold plate, 10. Lower mold plate, 11. Locating pin, 12. Inner hole, 13. Chamfer, 14. Head section, 15. Middle section, 16. Flange. DETAILED DESCRIPTION

[0029] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0031] See also Figures 1 to 4 , Example 1

[0032] This embodiment relates to a preferred embodiment of a positioning device for casting sand molds.

[0033] The positioning device for casting a sand mold comprises a positioning pin sleeve 1 and a positioning pin 11 that cooperate with each other.

[0034] Specifically, first is the locating pin sleeve 1, which is installed on the upper mold plate 9 through clearance fit, including an inner hole 12 that cooperates with the locating pin 11. The size of the inner hole 12 of the locating pin sleeve 1 matches the size of the locating pin 11, and the accurate positioning of the locating pin sleeve 1 and the locating pin 11 can be achieved through clearance fit.

[0035] Furthermore, the bottom of the inner hole 12 of the positioning pin sleeve 1 is provided with a circle of chamfers 13 to guide the insertion of the positioning pin 1. When the positioning pin 11 is inserted into the positioning pin sleeve 1, the head of the positioning pin 11 first contacts the entrance of the inner hole 12. The chamfered hole is smoother and reduces insertion resistance, allowing the positioning pin to enter the inner hole more easily and smoothly.

[0036] In more detail, an exhaust hole 6 is provided at the top of the positioning pin sleeve 1 , a through hole 2 is provided in the middle of the positioning pin sleeve 1 , and a fastening groove 7 is provided on the outer peripheral surface of the positioning pin sleeve 1 .

[0037] For example, in an optional situation, the exhaust hole 6 at the top of the positioning pin sleeve 1 is a through hole that passes through the positioning pin sleeve 1 and is connected to the inner hole 12, which can effectively exhaust the internal gas and avoid defects such as air holes.

[0038] Taking an optional situation as an example, the positioning pin sleeve 1 is provided with at least four through holes 2, and the four through holes 2 are evenly distributed along the circumference of the middle part of the positioning pin sleeve 1, so as to facilitate the uniform distribution of the airflow when the positioning pin sleeve 1 cooperates with the positioning pin 11, thereby further improving the exhaust effect.

[0039] Taking an optional situation as an example, the positioning pin sleeve 1 is provided with at least three fastening grooves 7, which are circumferentially spaced along the outer peripheral surface of the positioning pin sleeve 1, thereby enhancing the interaction force between the positioning pin sleeve 1 and the molding sand during the sand filling and tamping process, thereby making the entire assembly tighter, allowing the molding sand to be better embedded in the positioning pin sleeve 1, and facilitating smooth demolding when opening the mold.

[0040] Next is the positioning pin 11 , which is divided into an upper half and a lower half. The lower half is mounted on the lower mold plate 10 , and the upper half extends upward to cooperate with the inner hole 12 of the positioning pin sleeve 1 .

[0041] In more detail, the positioning pin 11 includes two integrally formed head sections 14 with an inclination and a cylindrical middle section 15. The middle position of the middle section of the positioning pin 11 has a flange 16 surrounding the middle section. The flange 16 forms an upper half and a lower half of the positioning pin 11.

[0042] Since both head sections 14 of the positioning pin 11 have a certain inclination angle, they can be smoothly matched with the positioning pin sleeve 1 during installation.

[0043] In more detail, a longitudinal exhaust groove 5 is provided at the position where the middle section 15 of the positioning pin 11 cooperates with the positioning pin sleeve 1 .

[0044] For example, in an optional embodiment, the positioning pin 11 is provided with at least four exhaust grooves 5, which are evenly distributed along the circumference of the middle section of the positioning pin 11. The provision of the exhaust grooves 5 not only facilitates the fit between the two and reduces wear during fit, but also facilitates the exhaust of gas during sand filling.

[0045] Preferably, the positioning pin sleeve 1 and the positioning pin 11 are both made of 45 steel, because it has high tensile strength and high yield, wear resistance, corrosion resistance and other excellent mechanical properties, which makes it fully sufficient in terms of strength matching and requires tempering treatment. Example 2

[0046] Based on Example 1, this embodiment provides a casting sand mold, including: an upper molding sand box 8, a lower molding sand box 4, an upper mold plate 9 cooperating with the upper molding sand box 8, a lower mold plate 10 cooperating with the lower molding sand box 4, and a positioning device provided in the inner cavity of the upper molding sand box 8 and the lower molding sand box 4, through which the positioning and guiding of the upper molding sand box 8 and the lower molding sand box 4 are completed.

[0047] The working principle of the utility model for casting sand mold is:

[0048] Molding sand upper box: Assemble the positioning pin sleeve 1 on the upper mold plate 9 through clearance fit, fill the resin sand into the molding sand upper box 8, and compact it around the upper mold plate 9. Since the outer ring of the positioning pin sleeve 1 has three circumferential fastening grooves 7, the positioning pin sleeve 1 can fit tightly with the molding sand;

[0049] When the mold is opened, due to the function of the fastening groove 7, the positioning pin sleeve 1 can be firmly attached to the upper box 8 of the molding sand and be taken away together with the molding sand, thereby achieving the fixation of the positioning pin sleeve 1 and the smooth demoulding of the casting;

[0050] Sand lower box: The lower half of the positioning pin 11 is fixed on the lower mold plate 10, and the upper half extends to cooperate with the positioning pin sleeve 1 in the sand upper box. Then, when resin sand is placed around the lower mold plate 10 to fill the mold, the positioning pin hole is naturally formed;

[0051] After the upper and lower boxes are shaped and the paint is dried, the entire locating pin 11 is inserted into the pin hole of the lower box 4 of the molding sand, and then the upper and lower boxes are combined together to form a complete mold. After the boxes are combined, the locating pin sleeve 1 in the upper box is aligned with the locating pin 1 in the lower box, thus completing the precise positioning and guiding of the boxes. After molding, they are opened and closed smoothly along the parting surface 3.

[0052] During the closing process, the upper and lower boxes can be accurately aligned in a predetermined manner, thus avoiding casting defects caused by misalignment or deviation. At the same time, this positioning and guiding function also helps to improve production efficiency and casting quality.

[0053] The beneficial effects of the positioning device for casting sand mold and the sand mold of the utility model are:

[0054] The use of the positioning pin sleeve and the positioning pin, and the positioning fit between metals, completes the precise positioning and guide closing, greatly improving the fitting accuracy;

[0055] This positioning and guiding function can avoid product defects caused by misalignment or deviation, help improve production efficiency and product quality, and has low production costs, high flexibility, and can be recycled and reused, saving costs;

[0056] The main usage scenarios are manual resin sand molding products, generally non-standard or heavy-duty large products, and its superior performance is particularly prominent for medium and large castings.

[0057] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A positioning device for casting sand mold, characterized in that, include: A positioning pin sleeve is installed on the upper mold plate through a clearance fit, and the positioning pin sleeve includes an inner hole that cooperates with the positioning pin, a vent hole is provided at the top of the positioning pin sleeve, a through hole is provided in the middle, and a fastening groove is provided on the outer peripheral surface; The locating pin has its lower half mounted on the lower mold plate, and its upper half extends upward to cooperate with the inner hole of the locating pin sleeve. The locating pin includes two integrally formed head sections with an inclination and a cylindrical middle section. A longitudinal exhaust groove is also provided at the position where the middle section of the locating pin cooperates with the locating pin sleeve.

2. The positioning device for casting sand mold according to claim 1, characterized in that: The inner hole size of the positioning pin sleeve matches the size of the positioning pin, and positioning is achieved through clearance fit.

3. The positioning device for casting sand mold according to claim 1, characterized in that: The bottom of the inner hole of the positioning pin sleeve is provided with a circle of chamfers for guiding the insertion of the positioning pin.

4. The positioning device for casting sand mold according to claim 1, characterized in that: The exhaust hole at the top end of the positioning pin sleeve is a through hole, which passes through the positioning pin sleeve and is connected with the inner hole.

5. The positioning device for casting sand mold according to claim 1, characterized in that: At least four through holes are provided and are evenly distributed along the circumference of the middle portion of the positioning pin sleeve.

6. The positioning device for casting sand mold according to claim 1, characterized in that: At least three fastening grooves are provided and are distributed circumferentially and spaced apart along the outer circumferential surface of the positioning pin sleeve.

7. The positioning device for casting sand mold according to claim 1, characterized in that: The middle position of the middle section of the positioning pin is provided with a flange which surrounds the middle section, and the flange forms an upper half and a lower half of the positioning pin.

8. The positioning device for casting sand mold according to claim 1, characterized in that: At least four exhaust grooves are provided and are evenly distributed along the circumference of the middle section of the positioning pin.

9. A sand mold, characterized in that: include: An upper molding sand box, a lower molding sand box, an upper mold plate that cooperates with the upper molding sand box, a lower mold plate that cooperates with the lower molding sand box, and a positioning device as described in any one of claims 1 to 8, through which the positioning and guiding of the upper molding sand box and the lower molding sand box are completed.

Images