Active negative pressure exhaust device for differential pressure die

Abstract

The utility model relates to the field of aluminum alloy hub differential pressure casting molds, and discloses an active negative pressure exhaust device for a differential pressure mold, which comprises a mold body, an exhaust pipe for exhausting air in a mold cavity is communicated with the mold body, the tail end of the exhaust pipe is connected with a reducer pipe, and the small-caliber position of the middle section of the reducer pipe is communicated with the exhaust pipe. The two ends of the reducer pipe are connected with an air inlet nipple and an air outlet nipple respectively, and the air inlet pipe is communicated with a compressed air source. According to the utility model, an attractive force with certain strength can be generated for gas in the mold cavity, the active exhaust rate of the gas in the mold cavity is accelerated, and the exhaust efficiency of the mold is effectively improved, so that the resistance effect of the gas in the mold cavity on molten aluminum in the mold filling process is reduced, and the service life of the mold is prolonged. The risk that air is involved into the casting to cause air hole waste is reduced, especially the problem of the yield of the long-arm casting is solved, and the casting quality of the product is guaranteed; and the exhaust insert is arranged, so that the exhaust pipe is convenient to disassemble, assemble, replace and maintain under the conditions of abrasion, blockage and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to aluminum alloy wheel hub differential pressure casting mould field especially relates to a kind of active negative pressure exhaust device for differential pressure mould. BACKGROUND

[0002] Differential pressure casting is a kind of active negative pressure exhaust device for differential pressure mould by the different pressure of upper and lower pressure chamber to control metal liquid filling and solidification process.It is on the basis of low-pressure casting, and sealing cover is provided on the outer cover of casting mould, and compressed air is introduced into crucible and sealing cover, but the pressure in crucible is slightly higher, so that metal liquid in crucible fills casting mould under the action of pressure difference through riser pipe.Because there is pressure in upper and lower pressure chamber, metal liquid rises steadily, reduces turbulence, then adjusts pressure difference in solidification stage, promotes feeding, reduces shrinkage, and greatly improves the mechanical properties of casting.

[0003] Because differential pressure casting mould is in closed mould cavity, and there is pressure in sealing cover, it is difficult to exhaust gas in mould when aluminum liquid fills.The gas that is not exhausted in time is rolled into aluminum liquid in filling process, and after aluminum liquid solidifies, gas exists in the form of blowhole in casting, thereby producing blowhole defect waste product.Especially for long-arm casting, because long-arm casting is relatively long, and the distance from riser to distal end position is prone to air pocket phenomenon, gas is concentrated in distal end or high point of mould cavity, resulting in blowhole defect waste product, which seriously restricts the yield of long-arm casting.

[0004] Therefore, it is an urgent problem to be solved to develop a kind of active negative pressure exhaust device for differential pressure mould applied to differential pressure casting production. UTILITY MODEL CONTENTS

[0005] The utility model aims at the above problems, and provides a kind of active negative pressure exhaust device for differential pressure mould to solve the problem that gas in cavity is not easy to exhaust in the use process of existing differential pressure casting mould, prone to blowhole defect, and the problem of low yield of long-arm casting.

[0006] To solve the above technical problems, the utility model adopts the technical scheme that:

[0007] A kind of active negative pressure exhaust device for differential pressure mould, including mould body, the mould body is connected with the exhaust pipe for mould cavity exhaust, the tail end of the exhaust pipe is connected with reducing pipe, the middle segment small caliber of the reducing pipe is communicated exhaust pipe, and the both ends of reducing pipe are respectively connected with gas inlet pair of wires and exhaust port pair of wires, and gas inlet pair of wires is communicated compressed gas source.

[0008] Preferably, the front end of the exhaust pipe is connected with an exhaust insert, and the mold body is connected with the exhaust insert through the exhaust insert, a mounting hole is formed in the mold body corresponding to the exhaust insert, the exhaust insert is detachably mounted in the mounting hole, an exhaust hole is formed in the exhaust insert and communicated with the mold cavity, and the front end of the exhaust pipe is communicated with the exhaust hole.

[0009] Preferably, a exhaust plug is arranged in the exhaust hole, the exhaust plug is in a cylindrical structure, and exhaust eyes are densely arranged on the exhaust plug in an axial direction.

[0010] Preferably, the diameter of the exhaust eyes is 0.1-0.2 mm.

[0011] Preferably, the bottom of the exhaust insert is made according to the profile of the mold cavity, and transverse and longitudinal staggered exhaust grooves are formed in the bottom of the exhaust insert and communicated with the exhaust hole.

[0012] Preferably, an exhaust gap is arranged between the exhaust insert and the mold body, the exhaust gap is formed between the exhaust insert and the mold body, and the exhaust gap is communicated with the atmosphere.

[0013] Preferably, the exhaust grooves are communicated with the exhaust gap, so that the gas collected by the exhaust grooves can be discharged through the exhaust gap.

[0014] The beneficial effects of the utility model lie in that: the utility model discloses a variable-diameter pipe communicated with an exhaust pipe, when compressed air flows through the small-diameter part of the variable-diameter pipe, the flow rate of the compressed air will increase due to the decrease of the inner diameter, and a local low-pressure area is formed in the connecting area of the variable-diameter pipe and the exhaust pipe, and a certain negative pressure is generated in the exhaust pipe, which generates a certain strength of suction force on the gas in the mold cavity, accelerates the active discharge rate of the gas in the mold cavity, and effectively improves the mold exhaust efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0015] The utility model will be explained further in detail in combination with the drawings and specific embodiments.

[0016] Figure 1 It is a three-dimensional structure schematic view of the utility model.

[0017] Figure 2 It is a sectional view of the utility model in use state.

[0018] Figure 3 It is Figure 2 the bottom view.

[0019] In the figure: 10 - mold body; 20 - exhaust pipe; 21 - reducing pipe; 22 - air inlet pair of wires; 23 - exhaust port pair of wires; 30 - exhaust insert; 31 - exhaust hole; 32 - exhaust plug; 33 - exhaust groove; 34 - exhaust slot; 35 - exhaust eye.

[0020] The arrow in the figure shows the direction of the air flow. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments.

[0022] As Figures 1-3 shown, an active negative pressure exhaust device for a differential pressure mold, comprising a mold body 10, the mold body 10 is communicated with an exhaust pipe 20 for mold cavity exhaust, the tail end of the exhaust pipe 20 is connected with a reducing pipe 21, the middle section small caliber of the reducing pipe 21 is communicated with the exhaust pipe 20, the two ends of the reducing pipe 21 are connected with an air inlet pair of wires 22 and an exhaust port pair of wires 23 respectively, and the air inlet pair of wires 22 is communicated with a compressed air source. When using, the compressed air source supplies compressed air into the reducing pipe 21, when the compressed air flows through the small caliber, because the inner diameter of the reducing pipe 21 is reduced, the flow rate of the compressed air will increase, and a local low pressure area is formed in the connecting area of the reducing pipe 21 and the exhaust pipe, at the same time, a certain negative pressure is generated in the exhaust pipe 20, a certain strength of suction force is generated on the gas in the mold cavity, the active exhaust rate of the gas in the mold cavity is accelerated, and the mold exhaust efficiency is effectively improved. Thus, the resistance effect of the gas in the mold cavity on the aluminum liquid filling process is reduced, the risk of gas being rolled into the casting to cause blowhole waste products is reduced, especially the problem of long arm casting yield is improved, and the product casting quality is ensured.

[0023] As a preferred embodiment, the front end of the exhaust pipe 20 is connected with an exhaust insert 30, and the exhaust insert 30 is connected with the mold body 10. Specifically, a mounting hole is formed on the mold body 10 corresponding to the exhaust insert 30, the exhaust insert 30 is detachably mounted in the mounting hole, an exhaust hole 31 communicating with the mold cavity is formed on the exhaust insert 30, and the front end of the exhaust pipe 20 communicates with the exhaust hole 31. In this embodiment, the exhaust pipe 20 and the exhaust insert 30 are integrated into a modular structure, which facilitates the disassembly, replacement and maintenance of the exhaust pipe 20 when the exhaust pipe 20 is worn, blocked or the like, and improves the equipment inspection and maintenance efficiency.

[0024] Preferably, an exhaust plug 32 is provided inside the exhaust hole 31. The exhaust plug 32 has a cylindrical structure and is densely covered with through exhaust holes 35 along the axial direction. Preferably, the diameter of the exhaust holes 35 is 0.1-0.2 mm, which ensures normal venting while effectively blocking molten aluminum and preventing leakage. The exhaust plug 32 increases the venting area and further accelerates the venting rate.

[0025] Preferably, the bottom of the venting insert 30 is made to conform to the profile of the mold cavity, and the bottom of the venting insert 30 is provided with crisscrossing venting grooves 33. The venting grooves 33 are connected to the venting holes 31, so that the bottom of the entire venting insert 30 can serve as the venting structure of the mold cavity, further increasing the venting area.

[0026] Preferably, such as Figure 3 As shown, an exhaust slit 34 is provided between the exhaust insert 30 and the mold body 10. The exhaust slit 34 is formed by the gap between the exhaust insert 30 and the mold body 10. The exhaust slit 34 is connected to the outside atmosphere as another exhaust channel of the mold cavity.

[0027] Preferably, the exhaust groove 33 is connected to the exhaust slit 34, so that the gas collected by the exhaust groove 33 can also be discharged through the exhaust slit 34.

[0028] The above-disclosed embodiments are merely specific examples of this utility model, but this utility model is not limited thereto. For those skilled in the art, any modifications made without departing from the principle of this utility model should be considered as protected by this utility model.

Claims

1. An active negative pressure exhaust device for differential pressure molds, characterized in that: Includes a mold body (10), on which an exhaust pipe (20) for venting the mold cavity is connected. The tail end of the exhaust pipe (20) is connected to a reducing pipe (21). The middle section of the reducing pipe (21) with a small diameter is connected to the exhaust pipe (20). The two ends of the reducing pipe (21) are respectively connected to an air inlet wire (22) and an exhaust wire (23). The air inlet wire (22) is connected to a compressed air source.

2. The active negative pressure exhaust device for differential pressure molds according to claim 1, characterized in that: The exhaust pipe (20) is connected to the exhaust insert (30) at the front end and is connected to the mold body (10) through the exhaust insert (30). The mold body (10) has an assembly hole corresponding to the exhaust insert (30). The exhaust insert (30) is detachably installed in the assembly hole. The exhaust insert (30) has an exhaust hole (31) that connects to the mold cavity. The front end of the exhaust pipe (20) connects to the exhaust hole (31).

3. The active negative pressure exhaust device for differential pressure molds according to claim 2, characterized in that: An exhaust plug (32) is provided inside the exhaust hole (31). The exhaust plug (32) is a cylindrical structure, and through exhaust holes (35) are densely distributed along the axial direction on the exhaust plug (32).

4. The active negative pressure exhaust device for differential pressure molds according to claim 3, characterized in that: The diameter of the exhaust port (35) is 0.1-0.2 mm.

5. The active negative pressure exhaust device for differential pressure molds according to claim 2, characterized in that: The bottom of the venting insert (30) is made to conform to the profile of the mold cavity, and the bottom of the venting insert (30) is provided with crisscrossing venting grooves (33), which are connected to the venting holes (31).

6. The active negative pressure exhaust device for differential pressure molds according to claim 2, characterized in that: An exhaust slit (34) is provided between the exhaust insert (30) and the mold body (10). The exhaust slit (34) is formed by the gap between the exhaust insert (30) and the mold body (10) and is connected to the outside atmosphere.

7. The active negative pressure exhaust device for differential pressure molds according to claim 5, characterized in that: The exhaust groove (33) is connected to the exhaust slit (34), so that the gas collected by the exhaust groove (33) can be discharged through the exhaust slit (34).

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