Valve type hot runner structure of mold

Abstract

The invention provides a valve type hot runner structure of a mold, and belongs to the technical field of molds. The problem that an existing mold is unstable when driving a valve needle to move is solved. According to the valve type hot runner structure of the mold, the mold comprises a fixed mold, a hot runner is formed in the fixed mold, a valve needle is arranged in the hot runner in a penetrating mode, the valve type hot runner structure comprises a cylinder body fixed to the fixed mold and a sliding plug arranged in the cylinder body, a buffering hole is formed in the sliding plug, and the top end of the valve needle is inserted into the buffering hole of the sliding plug in a sliding mode. The top end of the sliding plug is in threaded connection with an adjusting bolt, a buffer spring located between the adjusting bolt and the top end of the valve needle is arranged in the sliding plug, and the sliding plug can do reciprocating linear movement in the cylinder body in the axial direction of the valve needle. The valve type hot runner structure of the mold is more compact, and the moving stability of the valve needle is also improved.

Description

Technical Field

[0001] The invention belongs to the technical field of molds and relates to a valve-type hot runner structure of a mold. Background Art

[0002] In the field of injection molds, hot runner technology has been widely used. Hot runner technology can not only reduce the waste of plastic materials, but also shorten the molding cycle and improve production efficiency. After the product is filled each time, the valve needle will seal the gate, thereby improving the product's qualification rate.

[0003] The gate advantage of this mold is that the product has no material head, so the gate is directly placed on the product appearance surface. Once the valve needle is closed, only a ring mark can be seen around the gate, and the diameter of the ring mark is the same as the gate diameter. For example, the Chinese patent application [Grant Announcement No.: CN206568477U] discloses a needle valve hot runner mold and a valve needle assembly, including a power unit and a valve needle connected to the power unit, and also a valve needle plate. The power unit drives multiple valve needles to perform reciprocating linear motion along the axial direction of the valve needle through the valve needle plate. The power unit includes at least one cylinder or oil cylinder.

[0004] The above structure drives the valve needle plate to move by the power unit, and the valve needle plate drives multiple valve needles to move back and forth along the axial direction of the valve needle, so that the power unit has a larger driving force when driving the valve needle plate to move. The valve needle plate needs to drive multiple valve needles to move when moving, resulting in unstable movement of the valve needle, affecting the coordination between the valve needle and the mold, and easily causing flash on the gate. Summary of the invention

[0005] The purpose of the present invention is to address the above-mentioned problems in the prior art and to propose a valve-type hot runner structure for a mold. The technical problem to be solved by the present invention is: how to solve the problem of instability when the valve needle is driven to move by the prior mold.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A valve type hot runner structure of a mold, the mold includes a fixed mold, a hot runner is opened on the fixed mold, a valve needle is inserted in the hot runner, and the valve type hot runner structure includes a cylinder body fixed on the fixed mold and a sliding plug arranged in the cylinder body, a buffer hole is opened on the sliding plug, the top end of the valve needle is slidably inserted into the buffer hole of the sliding plug, the top end of the sliding plug is threadedly connected with an adjusting bolt, the sliding plug is provided with a buffer spring located between the adjusting bolt and the top end of the valve needle, and the sliding plug can make reciprocating linear movements in the cylinder body along the axial direction of the valve needle.

[0008] Working principle: the valve needle is inserted into the hot runner of the fixed mold, a cylinder body is fixed on the fixed mold, a sliding plug is arranged in the cylinder body, a buffer hole is opened on the sliding plug, and the top end of the valve needle is slidably inserted into the buffer hole of the sliding plug. After the mold is closed, the molten raw material enters the molding cavity through the hot runner. At this time, the valve needle does not block the gate. When the molten raw material in the molding cavity is sufficient, the sliding plug can make a reciprocating linear movement along the axial direction of the valve needle in the cylinder body. The movement of the sliding plug drives the valve needle to move, and the valve needle moves linearly toward the molding cavity. A buffer spring is arranged between the adjusting bolt in the sliding plug and the top of the valve needle to buffer the impact, reduce the impact force, and avoid the cracking failure of the gate under the action of fatigue stress. The valve needle of the sliding plug is driven to move by the linear movement of the sliding plug in the cylinder body. The sliding plug moves along the inner wall of the cylinder body when moving, which has a guiding effect on the movement of the sliding plug, improves the stability of the movement of the sliding plug, and also improves the stability of the movement of the valve needle, so that the valve needle can stably block the gate and improve the stability of the movement of the valve needle.

[0009] More importantly, the present application directly opens the buffer hole on the sliding plug in the cylinder body, and then replaces the existing piston rod with the valve needle. The piston rod extends into the cylinder body, and the top end of the piston rod is inserted into the buffer hole of the sliding plug. The buffer spring is also integrated into the cylinder body. Compared with the existing method of directly setting the elastic part on the outside of the driving part, the structure is more compact and the stability is higher.

[0010] In the valve-type hot runner structure of the above-mentioned mold, a fixed mold panel is connected to the fixed mold, and an adjustment hole is opened on the fixed mold panel. The adjustment hole and the adjustment bolt are arranged opposite to each other along the axial direction of the valve needle.

[0011] After long-term use, each movement of the valve needle has a certain impact on the gate. The buffer spring is used to reduce the impact of the valve needle on the gate. When the valve needle and the mold gate need to be adjusted, the valve needle can be adjusted by inserting tool pliers from the adjustment hole into the makeshift cavity and removing the adjusting bolt. The taper of the tail of the valve needle is adjusted in coordination with the taper of the mold gate, making the adjustment of the valve needle more convenient. The compression degree of the buffer spring can also be adjusted by rotating the adjusting bolt, thereby ensuring that the buffer spring can always play a good damping role during long-term use, facilitating the maintenance of the valve needle, greatly improving the work efficiency and maintenance efficiency, and ensuring the yield rate of the mold after long-term use.

[0012] In the valve type hot runner structure of the above-mentioned mold, the top of the valve needle has a limit shoulder, and the sliding plug has an annular limit edge. One end of the limit shoulder and one end of the limit edge are abutted against each other along the axial direction of the valve needle. The outer side wall of the limit shoulder has a planar limit wall, and the limit wall can be close to or fit with the inner side wall of the sliding plug.

[0013] The top of the valve needle realizes the rapid positioning of the valve needle and the slider by setting the limit stop shoulder on the limit stop edge, and prevents the valve needle from circumferential rotation during the buffering process through the cooperation between the limit wall and the inner wall of the slide plug, so that the valve needle only moves along its axial straight line, ensuring that the valve needle can stably block the gate and improving the accuracy of the mold.

[0014] In the valve-type hot runner structure of the above-mentioned mold, the inner side wall of the sliding plug protrudes inward to form a blocking portion, and the blocking portion is arranged in a one-to-one correspondence with the limiting wall, and the blocking portion is close to or fits with the corresponding limiting wall.

[0015] The cooperation between the blocking part and the limiting wall enables the top of the valve needle to be prevented from circumferential rotation through the cooperation of the limiting wall of the limiting shoulder, thereby achieving the purpose of improving the mold precision.

[0016] In the valve hot runner structure of the above-mentioned mold, the middle part of the outer wall of the sliding plug bulges circumferentially to form a sliding ring, and two air vents are opened on the cylinder body, which are respectively located at the two ends of the sliding ring along the axial direction of the valve needle.

[0017] When driving the valve needle to move linearly, gas is introduced from the vent near the top of the cylinder body to push the sliding ring of the sliding plug to move along the cylinder body. The sliding plug drives the valve needle to move axially and linearly synchronously, so that the valve needle closes the gate. When the gate needs to be opened, gas is directly introduced into another vent to push the sliding ring of the sliding plug to move in the opposite direction. The setting of the sliding ring makes it more convenient to drive the sliding plug to move, and the sliding plug can be pushed to move more stably.

[0018] In the valve-type hot runner structure of the above-mentioned mold, two limiting walls are provided, the two limiting walls are connected by two arc-shaped mounting walls, and the two limiting walls are symmetrically arranged along the axial direction of the valve needle.

[0019] The setting of two limiting walls requires less processing on the original valve needle top and also retains more of the valve needle's upper top surface for the buffer spring to abut against. Through the cooperation of the installation wall and the limiting wall, the top of the valve needle fits with the inner wall of the sliding plug, and the top of the valve needle is set more stably.

[0020] In the valve-type hot runner structure of the above-mentioned mold, the valve needle is arranged at an angle, and the above-mentioned adjustment hole is opened on the side wall of the fixed mold panel. The adjustment hole is arranged at an angle and the inclination angle is the same as the inclination angle of the valve needle.

[0021] By opening the side wall of the fixed mold panel, since the fixed mold panel is usually connected to external components during the production process of the mold, if the opening at the end of the fixed mold panel affects the installation of the fixed mold panel, the opening in the side wall will not affect the installation of the fixed mold panel, and it is also convenient for adjusting the valve needle.

[0022] In the valve-type hot runner structure of the above-mentioned mold, a countersunk hole is opened on the top of the sliding plug, the head of the adjusting bolt is arranged in the countersunk hole, and the buffer spring is arranged between the end face of the valve needle and the stem of the adjusting bolt.

[0023] The setting of the countersunk hole makes the setting of the adjusting bolt more stable. When the overall compression of the buffer spring needs to be adjusted, a limit is formed on the adjusting bolt to prevent the adjusting bolt from being too embedded in the sliding plug when rotating, thereby making the adjustment more convenient and stable.

[0024] In the valve-type hot runner structure of the above-mentioned mold, the top end of the sliding plug is located outside the cylinder body, and a sealing ring is provided between the outer side wall of the top end of the sliding plug and the inner side wall of the cylinder body.

[0025] By setting the sealing ring, the gas overflow of the cylinder body is avoided and the stability of the cylinder drive is ensured.

[0026] Compared with the prior art, the present invention has the following advantages: the valve needle of the sliding plug is driven to move through the linear motion of the sliding plug in the cylinder body, and the sliding plug moves along the inner wall of the cylinder body when moving, which has a guiding effect on the movement of the sliding plug, thereby improving the stability of the movement of the sliding plug and the stability of the movement of the valve needle, so that the valve needle can stably seal the gate and improve the stability of the movement of the valve needle. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a cross-sectional view of the valve needle after the present invention is assembled.

[0028] Figure 2 yes Figure 1 A partial enlarged view of point A in the middle.

[0029] Figure 3 It is a structural schematic diagram of the sliding plug in the present invention.

[0030] Figure 4 It is a partial structural schematic diagram of the valve needle in the present invention.

[0031] In the figure, 1, fixed mold; 11, fixed mold frame; 12, fixed mold insert; 12a, cooling water jacket; 2, fixed mold panel; 21, adjusting hole; 3, valve needle; 31, limit shoulder; 31a, limit wall; 31b, mounting wall; 4, driving member; 41, cylinder body; 41a, piston chamber; 41b, vent; 6, sliding plug; 61, adjusting bolt; 62, limit stop edge; 63, blocking part; 64, countersunk hole; 65, sliding ring; 66, buffer hole; 7, buffer spring; 8, sealing ring; 9, hot runner. DETAILED DESCRIPTION

[0032] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0033] like Figure 1 As shown, the valve type hot runner structure of the mold comprises a fixed mold 1, a hot runner 9 is opened on the fixed mold 1, and a valve needle 3 is inserted into the hot runner 9.

[0034] Specifically, Figure 1-4 As shown, the valve type hot runner structure includes a cylinder body 41 fixed on the fixed mold 1 and a sliding plug 6 arranged in the cylinder body 41, a buffer hole 66 is opened on the sliding plug 6, the top end of the valve needle 3 is slidably inserted into the buffer hole 66 of the sliding plug 6, the top end of the sliding plug 6 is threadedly connected with an adjusting bolt 61, and a buffer spring 7 is arranged in the sliding plug 6 between the adjusting bolt 61 and the top end of the valve needle 3. The sliding plug 6 can make reciprocating linear movements in the cylinder body 41 along the axial direction of the valve needle 3.

[0035] Working principle: The valve needle 3 is inserted into the hot runner 9 of the fixed mold 1, a cylinder body 41 is fixed on the fixed mold 1, a sliding plug 6 is arranged in the cylinder body 41, and a buffer hole 66 is opened on the sliding plug 6. The top of the valve needle 3 is slidably inserted into the buffer hole 66 of the sliding plug 6. After the mold is closed, the molten material enters the molding cavity through the hot runner 9. At this time, the valve needle 3 does not block the gate. When the molten material in the molding cavity is sufficient, the sliding plug 6 can move back and forth in the cylinder body 41 along the axial direction of the valve needle 3. The movement of the sliding plug 6 drives the valve needle 3 to move, and the valve needle 3 moves straight toward the molding cavity. The sliding plug 6 moves linearly, and a buffer spring 7 is arranged between the adjusting bolt 61 in the sliding plug 6 and the top of the valve needle 3 to buffer the impact, reduce the impact force, and avoid the cracking failure of the gate under the action of fatigue stress. The sliding plug 6 moves linearly in the cylinder body 41, and the valve needle 3 of the sliding plug 6 is driven to move. When moving, the sliding plug 6 moves along the inner cavity wall of the cylinder body 41, which has a guiding effect on the movement of the sliding plug 6, improves the stability of the movement of the sliding plug 6, and also improves the stability of the movement of the valve needle 3, so that the valve needle 3 can stably block the gate, and the stability of the movement of the valve needle 3 is improved.

[0036] like Figure 2-4 As shown, a fixed mold panel 2 is connected to the fixed mold 1, and an adjustment hole 21 is opened on the fixed mold panel 2. The adjustment hole 21 and the adjusting bolt 61 are arranged opposite to each other along the axial direction of the valve needle 3. A limit stop shoulder 31 is provided on the top of the valve needle 3, and the sliding plug 6 has an annular limit stop edge 62. One end of the limit stop shoulder 31 and one end of the limit stop edge 62 abut against each other along the axial direction of the valve needle 3. A planar limit wall 31a is provided on the outer wall of the limit stop shoulder 31. The limit wall 31a can be close to or fit with the inner side wall of the sliding plug 6. A blocking portion 63 is formed by an inward protrusion on the inner side wall of the sliding plug 6. The blocking portion 63 is arranged one-to-one with the limit wall 31a, and the blocking portion 63 is close to or fits with the corresponding limit wall 31a. Two limit walls 31a are provided, and the two limit walls 31a are connected by two arc-shaped mounting walls 31b. The two limit walls 31a are symmetrically arranged along the axial direction of the valve needle 3.

[0037] like Figure 1 and Figure 2 As shown, the valve needle 3 is arranged at an angle, and the above-mentioned adjustment hole 21 is opened on the side wall of the fixed mold panel 2. The adjustment hole 21 is arranged at an angle and the inclination angle is the same as the inclination angle of the valve needle 3. A countersunk hole 64 is opened on the top of the sliding plug 6, and the head of the adjusting bolt 61 is arranged in the countersunk hole 64. The buffer spring 7 is arranged between the upper end surface of the valve needle 3 and the rod of the adjusting bolt 61.

[0038] like Figure 2 As shown, the mold also includes a driving member 4, which includes the above-mentioned cylinder body. The cylinder body 41 has a piston cavity 41a for the sliding plug 6 to move up and down. The middle part of the outer wall of the sliding plug 6 bulges circumferentially to form a sliding ring 65. The cylinder body 41 is provided with two air vents 41b, which are respectively located at the two ends of the sliding ring 65 along the axial direction of the valve needle 3. The end of the top of the sliding plug 6 is located outside the cylinder body 41, and a sealing ring 8 is provided between the outer wall of the top of the sliding plug 6 and the inner wall of the cylinder body 41.

[0039] like Figure 1 As shown, the fixed mold 1 includes a fixed mold frame 11 and a fixed mold insert 12 fixedly connected to the fixed mold frame 11 , a cooling water jacket 12 a is provided in the fixed mold insert 12 , the cooling water jacket 12 a is sleeved outside the valve needle 3 , and the cooling water jacket 12 a is located outside the bottom of the valve needle 3 .

[0040] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A valve-type hot runner structure of a mold, the mold comprising a fixed mold (1), a hot runner (9) is opened on the fixed mold (1), a valve needle (3) is inserted into the hot runner (9), and the characteristics are: The valve-type hot runner structure comprises a cylinder body (41) fixed on a fixed mold (1) and a sliding plug (6) arranged in the cylinder body (41); a buffer hole (66) is opened on the sliding plug (6); the top end of the valve needle (3) is slidably inserted into the buffer hole (66) of the sliding plug (6); the top end of the sliding plug (6) is threadedly connected with an adjusting bolt (61); a buffer spring (7) is arranged in the sliding plug (6) between the adjusting bolt (61) and the top end of the valve needle (3); and the sliding plug (6) can make reciprocating linear movements in the cylinder body (41) along the axial direction of the valve needle (3).

2. The valve type hot runner structure of the mold according to claim 1, characterized in that: The fixed die (1) is connected to a fixed die panel (2), an adjustment hole (21) is provided on the fixed die panel (2), and the adjustment hole (21) and the adjustment bolt (61) are arranged opposite to each other along the axial direction of the valve needle (3).

3. The valve type hot runner structure of the mold according to claim 1 or 2, characterized in that: The top of the valve needle (3) has a limit stop shoulder (31), and the sliding plug (6) has an annular limit stop edge (62). One end of the limit stop shoulder (31) and one end of the limit stop edge (62) abut against each other along the axial direction of the valve needle (3). The outer side wall of the limit stop shoulder (31) has a planar limit wall (31a), and the limit wall (31a) can be close to or fit with the inner side wall of the sliding plug (6).

4. The valve type hot runner structure of the mold according to claim 3, characterized in that: The inner side wall of the sliding plug (6) protrudes inwards to form a blocking portion (63), and the blocking portion (63) is arranged in a one-to-one correspondence with the limiting wall (31a), and the blocking portion (63) is close to or in contact with the corresponding limiting wall (31a).

5. The valve type hot runner structure of the mold according to claim 1 or 2, characterized in that: The middle portion of the outer wall of the sliding plug (6) protrudes in the circumferential direction to form a sliding ring (65), and the cylinder body (41) is provided with two vents (41b), which are respectively located at two ends of the sliding ring (65) along the axial direction of the valve needle (3).

6. The valve type hot runner structure of the mold according to claim 3, characterized in that: Two limiting walls (31a) are provided, the two limiting walls (31a) are connected via two arc-shaped mounting walls (31b), and the two limiting walls (31a) are symmetrically arranged along the axial direction of the valve needle (3).

7. The valve type hot runner structure of the mold according to claim 2, characterized in that: The valve needle (3) is arranged at an angle, and the above-mentioned adjustment hole (21) is opened on the side wall of the fixed mold panel (2). The adjustment hole (21) is arranged at an angle and the inclination angle is the same as the inclination angle of the valve needle (3).

8. The valve type hot runner structure of the mold according to claim 1 or 2, characterized in that: A countersunk hole (64) is provided at the top of the sliding plug (6), the head of the adjusting bolt (61) is arranged in the countersunk hole (64), and the buffer spring (7) is arranged between the end surface of the valve needle (3) and the stem of the adjusting bolt (61).

9. The valve-type hot runner structure of the mold according to claim 7, characterized in that: The top end of the sliding plug (6) is located outside the cylinder body (41), and a sealing ring (8) is provided between the outer side wall of the top end of the sliding plug (6) and the inner side wall of the cylinder body (41).

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