Rotating shaft positioning device for injection molding machine

Abstract

The utility model belongs to the technical field of injection molding, and particularly relates to a rotating shaft positioning device for an injection molding machine. The utility model provides a rotating shaft positioning device for an injection molding machine, which comprises a convex ring arranged on the top of a rotating shaft, a magnetic unit arranged on the convex ring, and an induction positioning unit arranged on the wall of an injection cylinder, and the magnetic unit comprises a fixing belt wound on the outer circumferential surface of the convex ring and a magnetic piece arranged on the surface of the fixing belt, so that the linear position of the rotating shaft can be positioned through a light and simple structure, and the influence on the injection of the rotating shaft in injection equipment such as an injection molding machine and an injection molding machine is reduced to a great extent.

Description

Technical Field

[0001] The utility model belongs to the technical field of injection molding, and particularly relates to a rotating shaft positioning device for an injection molding machine. Background Art

[0002] In equipment such as injection molding machines, semi-solid magnesium alloy molding machines, and injection molding machines, single-cylinder injection is often adopted. When the piston rod of the cylinder pushes the screw for injection, it is also necessary to rotate to drive the screw to rotate. At this time, the component connected to the tail of the screw is a rotating shaft that will move linearly. To measure the position and movement displacement of this position, a common method in the industry is to add bearings and flanges to the rotating shaft. The flange moves back and forth with the rotating shaft but does not rotate. By detecting the position and movement displacement of the flange, the position and displacement of the rotating shaft are equivalently obtained.

[0003] The Chinese utility model patent with the patent publication number CN214867137U and the publication date of November 26, 2021, discloses a semi-solid magnesium alloy molding machine injection position detection and rotation system integrated mechanism, including an injection rod. The injection rod makes axial forward and backward translation and rotational motion. A collection head support is installed at the front end of the injection rod. The collection head support is rotatably connected to the injection rod. A linear motion guide is arranged on one side of the collection head support. The linear motion guide is used to limit the rotational motion of the collection head support. A position data collection head is installed on the collection head support. A position magnetic strip is arranged on one side of the position data collection head. The position magnetic strip is arranged in parallel with the injection rod in the same direction. The position data collection head collects the position signal of the injection rod through the position magnetic strip and sends the position signal to the PLC of the semi-solid magnesium alloy molding machine. The PLC controls the action of the injection rod according to the received position signal.

[0004] The general usage method and advantages of the semi-solid magnesium alloy molding machine injection position detection and rotation system integrated mechanism in the Chinese utility model patent are as follows: During operation, the injection rod of the semi-solid magnesium alloy molding machine rotates and moves horizontally in the axial direction to perform feeding and injection control. When the mold is closed in place, the injection rod starts to move forward. When the injection is in place, the injection rod rotates and the feeding mechanism moves synchronously in the axial direction. At this time, the position data collection head fixed on the collection head support starts to collect data, collects the signal and transmits it to the PLC of the semi-solid magnesium alloy molding machine. The PLC controls the injection action according to the received position signal, thereby forming a complete injection control system, and performing cyclic actions as described above. The advantage is that when the injection rod rotates and moves axially at the same time, only the axial forward and backward movement of the injection rod is detected for data, and its rotational movement will not be affected.

[0005] However, during the actual use of the injection position detection and rotation system integration mechanism, there are at least the following deficiencies. In other words, these are the technical problems to be solved by the present utility model: The mechanical structure of the detection mechanism is complex, with many parts, which not only increases the cost but also increases the movement inertia during injection, resulting in a relatively large driving load impact.

[0006] Therefore, in summary, there is an urgent need for a simple and lightweight injection positioning device to solve such problems. Summary of the Utility Model

[0007] The present utility model provides a rotating shaft positioning device for an injection molding machine, including a convex ring provided on the top of the rotating shaft, a magnetic unit provided on the convex ring, and an induction positioning unit installed on the barrel wall of the injection cylinder. The magnetic unit includes a fixing band wound around the outer circumferential surface of the convex ring and magnetic members provided on the surface of the fixing band, such that: The present utility model can achieve the positioning of the linear position of the rotating shaft through a lightweight and simple structure, and greatly reduces the influence on the injection of the rotating shaft in injection equipment such as injection molding machines and injection machines.

[0008] The technical solution adopted by the present utility model to solve the above problems is: A rotating shaft positioning device for an injection molding machine includes a convex ring provided on the top of the rotating shaft, a magnetic unit provided on the convex ring, and an induction positioning unit installed on the barrel wall of the injection cylinder; The magnetic unit includes a fixing band wound around the outer circumferential surface of the convex ring and magnetic members provided on the surface of the fixing band.

[0009] A further preferred technical solution lies in: The magnetic member includes a magnetic strip.

[0010] A further preferred technical solution lies in: The magnetic member includes a plurality of magnetic bars distributed along the winding direction of the fixing band.

[0011] A further preferred technical solution lies in: The convex ring includes a ring body, a first limiting ring and a second limiting ring that are arranged in parallel on the outer circumferential surface of the ring body and are used to form a groove for fixing the fixing band.

[0012] A further preferred technical solution lies in: The induction positioning unit includes a magnetic induction ruler provided above the rotating shaft for detecting the position of the magnetic member.

[0013] A further preferred technical solution lies in: The induction positioning unit includes a positioning and guiding assembly provided above the rotating shaft and sliding under the action of the magnetic member.

[0014] A further preferred technical solution is that: the positioning and guiding assembly includes a guiding strip installed on the injection barrel and arranged axially along the rotation axis, a through groove provided on one side of the guiding strip close to the magnetic member, and a magnetic block slidably connected in the through groove and moving under the action of the magnetic member.

[0015] A further preferred technical solution is that: the positioning and guiding assembly further includes a guiding groove provided on the inner wall of the side end of the through groove, and a protrusion provided on the side end of the magnetic block and slidably connected with the guiding groove.

[0016] A further preferred technical solution is that: the positioning and guiding assembly further includes a ball provided between the guiding groove and the protrusion.

[0017] A further preferred technical solution is that: an anti-slip layer is provided on the contact surface of the fixing belt close to the convex ring.

[0018] The beneficial effects brought by the present utility model: The rotation axis positioning device for an injection molding machine described in the present utility model achieves the same technical effects through a simpler structure compared with the existing structure. Further, this structure can effectively reduce the influence of the positioning device itself on the injection of the rotation axis and has better application prospects. Description of the Drawings

[0019] Figure 1 is the overall schematic diagram of the present utility model;

[0020] Figure 2 is the front view of Embodiment 1 of the present utility model;

[0021] Figure 3 is the front view of Embodiment 2 of the present utility model;

[0022] Figure 4 is the front view of Embodiment 3 of the present utility model;

[0023] Figure 5 is the bottom view of the induction positioning unit of the present utility model.

[0024] In the figure, the meanings of the following reference numerals are as follows:

[0025] Rotation axis a;

[0026] Convex ring 1, magnetic unit 2, induction positioning unit 3;

[0027] Ring body 11, first limit ring 12, second limit ring 13, fixing belt 21, magnetic member 22, magnetic induction ruler 31, positioning and guiding assembly 32;

[0028] Guiding strip 321, through groove 322, magnetic block 323, guiding groove 324, protrusion 325, ball 326. Detailed implementation manners

[0029] The following will describe in detail the embodiments of the present utility model with reference to the accompanying drawings. The following is only the preferred embodiment of the present utility model, and does not limit the scope of the present utility model.

[0030] The orientation terms such as up, down, left, right, front, back, front side, back side, top, bottom, etc. mentioned or possibly mentioned in this specification are defined relative to the structures shown in the respective drawings. The terms "inner" and "outer" respectively refer to the directions towards or away from the geometric center of a specific component. They are relative concepts and may accordingly change depending on their different positions and usage states. Therefore, these or other orientation terms should not be construed as restrictive terms.

[0031] Embodiment 1

[0032] As shown in the attached Figure 1-2 drawing, a rotary shaft positioning device for an injection molding machine includes a convex ring 1 provided on the top of a rotary shaft a, a magnetic unit 2 provided on the convex ring 1, and an induction positioning unit 3 installed on the barrel wall of the injection barrel; the magnetic unit 2 includes a fixing belt 21 wound around the outer circumferential surface of the convex ring 1, and magnetic members 22 provided on the surface of the fixing belt 21.

[0033] In this embodiment, the general usage method of the rotary shaft positioning device for an injection molding machine is as follows:

[0034] The rotary shaft a is arranged at the tail of the screw to drive the screw to rotate and move linearly for injection. Therefore, a magnetic unit 2 is provided as a magnetic field generator on the convex ring 1 on the top of the rotary shaft a, and an induction positioning unit 3 is installed on the inner wall of the barrel of the injection barrel, above the magnetic unit 2, as a magnetic field sensor. The function of the convex ring 1 is to eliminate the interference of the rotation process on the linear position detection. The gap between the induction positioning unit 3 and the magnetic unit 2 is preferably 2 ± 0.5 mm. The magnetic field sensor can detect the changes generated when the magnetic field generator passes through. These changes are sensed by a magnetosensitive sensor and converted into electrical signals. By processing and decoding these electrical signals, accurate displacement measurement results can be obtained; the magnetic unit 2 is composed of a fixing belt 21 fixed on the outer circumferential surface of the convex ring 11 and magnetic members 22 fixed on the surface of the fixing belt 21. The magnetic members 22 are preferably permanent magnets with their own magnetism.

[0035] As a preference of this embodiment, the magnetic member 22 includes a magnetic strip; the magnetic member 22 includes a plurality of magnetic strips distributed along the winding direction of the fixing belt 21; the convex ring 1 includes a ring body 11, a first limiting ring 12 and a second limiting ring 13 which are arranged in parallel on the outer circumferential surface of the ring body 11 and are used to form a groove for fixing the fixing belt 21; an anti-slip layer is provided on the contact surface of the fixing belt 21 close to the convex ring 1.

[0036] In this embodiment, the magnetic member 22 can be a single-piece flexible magnetic strip directly installed on the fixing belt 21, or a plurality of magnetic strips can be arranged closely on the fixing belt 21. Preferably, the magnetic strips are connected to each other without connection gaps. The first limiting ring 12 and the second limiting ring 13 on both sides of the ring body 11 form a groove for limiting the fixing belt 21 on the outer surface of the ring body 11 to improve the stability of detection. At the same time, the first limiting ring 12 and the second limiting ring 13 can be set as magnetic shielding rings to constrain the signal to be concentrated and emitted to the induction positioning unit 3; the fixing belt 21 can be installed on the surface of the ring body 11 in a detachable manner. For example, hooks for connecting the ends of the fixing belt 21 are provided at both ends of the fixing belt 21. To further improve the installation stability of the fixing belt 21 on the convex ring 1, an anti-slip layer is provided on the surface of the fixing belt 21 close to the convex ring 1, such as polyurethane, epoxy resin, methacrylate, etc.

[0037] As a preference of this embodiment, the induction positioning unit 3 includes a magnetic induction ruler 31 which is arranged above the rotating shaft a and is used to detect the position of the magnetic member 22.

[0038] In this embodiment, the magnetic induction ruler 31 is a magnetic sensor, covering the displacement range of the rotating shaft a, and realizes the positioning of the rotating shaft a by reading the position of the magnetic member 22. For example, a magnetic sensor disclosed in Chinese invention patent CN117872232A. It should be noted that the above magnetic sensor is a known technology for those skilled in the art.

[0039] Compared with the prior art, the advantages of this embodiment are as follows: The positioning device provided in this embodiment requires fewer parts than the existing structure, so the manufacturing cost is reduced. At the same time, the light structure makes its moment of inertia small when moving with the rotating shaft, and will not have a great impact on the injection process.

[0040] Embodiment Two

[0041] As shown in the attached Figure 3 and attached Figure 5 figures, the difference between this embodiment and Embodiment One is that another induction positioning unit is disclosed, which is specifically as follows:

[0042] The positioning and guiding assembly 32 includes a guiding strip 321 installed on the injection barrel and axially arranged along the rotation axis a, a through groove 322 provided on one side of the guiding strip 321 close to the magnetic member 22, and a magnetic block 323 slidably connected in the through groove 322 and moving under the action of the magnetic member 22; the positioning and guiding assembly 32 further includes a guiding groove 324 provided on the inner wall of the side end of the through groove 322, and a protrusion 325 provided on the side end of the magnetic block 323 and slidably connected with the guiding groove 324; the positioning and guiding assembly 32 further includes a ball 326 provided between the guiding groove 324 and the protrusion 325.

[0043] In this embodiment, the magnetic member 22 drives the magnetic block 323 in the positioning and guiding assembly 32 to slide in the through groove 322. A sensor is provided in the through groove 322. The position of the magnetic block 323 relative to the through groove 322 can be effectively determined by the signal change brought by the displacement when the magnetic block 323 slides in the through groove 322, or the signal change brought by the surface pressure in the through groove 322 during the sliding process, so as to determine the positions of the magnetic member 22 and the rotation axis a, and realize the positioning of the rotation axis.

[0044] The sensor can be set as a laser sensor provided at both ends of the through groove 322. A laser pulse is emitted by the laser. This laser pulse is aligned with the magnetic block 323 and is reflected and scattered. A part of the light returns to the receiver of the sensor. Then, the optical system on the receiver collects this part of the scattered light and images it on a highly sensitive light detection device such as a photodiode. These devices can convert the weak light signal into an electrical signal. By recording the time elapsed from the emission of the light pulse to the return reception, and combining the speed of light to calculate the target distance, the positioning of the magnetic block 323 driven by the magnetic member 22 can be realized; it can also be set as a pressure sensor, and the specific position of the magnetic block 323 can be determined by detecting and analyzing the pressure signals at different positions in the through groove 322, so as to realize the positioning of the rotation axis.

[0045] Compared with the prior art, the advantage of this embodiment is that it is not limited to the way of the magnetic sensor to read the position of the rotation axis. Instead, the magnetic member drives the magnetic block to move, and the movement of the magnetic block in the groove is determined by various ways such as pressure sensors, displacement sensors, and laser sensors to realize the positioning of the rotation axis, and the applicable scenarios are more extensive.

[0046] Embodiment Three

[0047] As shown in the attached Figure 4-5 figure, the difference between this embodiment and Embodiment One and Embodiment Two is that a positioning and guiding assembly 32 is added, and the specific details are as follows:

[0048] The induction positioning unit 3 includes a positioning and guiding assembly 32 disposed above the rotating shaft a and slidable under the action of the magnetic member 22; the positioning and guiding assembly 32 includes a guiding strip 321 mounted on the injection barrel and axially disposed along the rotating shaft a, a through groove 322 disposed on one side of the guiding strip 321 close to the magnetic member 22, and a magnetic block 323 slidably connected in the through groove 322 and movable under the action of the magnetic member 22; the positioning and guiding assembly 32 further includes a guiding groove 324 disposed on the inner wall of the side end of the through groove 322, and a protrusion 325 disposed on the side end of the magnetic block 323 and slidably connected to the guiding groove 324; the positioning and guiding assembly 32 further includes a ball 326 disposed between the guiding groove 324 and the protrusion 325.

[0049] In this embodiment, the positioning and guiding assembly 32 further improves the stability of detection. While detecting the position of the magnetic member 22 through the magnetic induction ruler 31, the magnetic member 22 synchronously drives the magnetic block 323 on the positioning and guiding assembly 32 to move on the surface of the magnetic induction ruler 31, effectively avoiding the problem that the magnetic induction ruler 31 fails to detect due to distance or other signal interferences; the guiding strip 321 is mounted on the wall of the injection barrel, preferably having legs such that the guiding strip 321 is located between the magnetic member 22 and the magnetic induction ruler 31, and further preferably disposed on the surface of the magnetic induction ruler 31 close to the magnetic member 22. The magnetic block 323 is slidably connected in the through groove 322. The magnetic block 323 undergoes displacement synchronously with the magnetic member 22 under the attraction of the magnetic member 22. The magnetic induction ruler 31 can read the magnetic change brought about by the sliding of the magnetic block 323 to position the position of the rotating shaft a; guiding grooves 324 are formed on the inner walls on both sides of the through groove 322 and connected to the protrusions 325 on both sides of the magnetic block 323 to limit the sliding of the magnetic block 323 to a certain extent, improving the stability of the device. To avoid the influence of friction on sliding and resulting in a decrease in measurement accuracy, balls 326 are disposed between the protrusion 325 and the guiding groove 324 to reduce the friction force.

[0050] Compared with the prior art, the advantages of this embodiment are as follows: effectively avoiding the situation where the magnetic induction ruler fails to detect due to external influences. When the magnetic induction ruler does not timely receive the magnetic signal emitted when the magnetic member passes by, the positioning and guiding assembly, under the action of the magnetic member, secondarily ensures that the magnetic induction ruler can effectively receive the signal emitted by the positioning and guiding assembly, strengthening the connection between the magnetic member and the magnetic induction ruler through a mechanical structure and improving the stability of the positioning device.

[0051] The embodiments of the present utility model have been described in detail above in conjunction with the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various modifications can be made without departing from the gist of the present utility model. These are all non-creative modifications and are protected by the Patent Law as long as they are within the scope of the claims of the present utility model.

Claims

1. A rotary shaft positioning device for an injection molding machine, characterized in that: It includes a convex ring (1) arranged on the top of a rotating shaft (a), a magnetic unit (2) arranged on the convex ring (1), and an induction positioning unit (3) installed on the wall of a cartridge case; the magnetic unit (2) includes a fixing band (21) wound around the outer circumferential surface of the convex ring (1), and magnetic members (22) arranged on the surface of the fixing band (21).

2. The rotary shaft positioning device for an injection molding machine according to claim 1, wherein: The magnetic members (22) include magnetic strips.

3. The rotary shaft positioning device for an injection molding machine according to claim 1, wherein: The magnetic members (22) include a plurality of magnetic bars distributed along the winding direction of the fixing band (21).

4. A rotary shaft positioning device for an injection molding machine according to claim 1, characterized in that: The convex ring (1) includes a ring body (11), a first limiting ring (12) and a second limiting ring (13) which are arranged in parallel on the outer circumferential surface of the ring body (11) and are used to form a groove for fixing the fixing band (21).

5. A rotary shaft positioning device for an injection molding machine according to claim 1, characterized in that: The induction positioning unit (3) includes a magnetic induction ruler (31) arranged above the rotating shaft (a) and used to detect the position of the magnetic members (22).

6. A rotary shaft positioning device for an injection molding machine according to any one of claims 1 or 5, characterized in that: The induction positioning unit (3) includes a positioning and guiding assembly (32) arranged above the rotating shaft (a) and sliding under the action of the magnetic members (22).

7. The rotary shaft positioning device for an injection molding machine according to claim 6, wherein: The positioning and guiding assembly (32) includes a guiding strip (321) installed on the cartridge case and arranged axially along the rotating shaft (a), a through groove (322) arranged on the side of the guiding strip (321) close to the magnetic members (22), and a magnetic block (323) slidably connected in the through groove (322) and moving under the action of the magnetic members (22).

8. The rotary shaft positioning device for an injection molding machine according to claim 7, characterized in that: The positioning and guiding assembly (32) further includes a guiding groove (324) arranged on the inner wall of the side end of the through groove (322), and a protrusion (325) arranged on the side end of the magnetic block (323) and slidably connected with the guiding groove (324).

9. The rotary shaft positioning device for an injection molding machine according to claim 8, wherein: The positioning and guiding assembly (32) further includes a ball (326) arranged between the guiding groove (324) and the protrusion (325).

10. A rotary shaft positioning device for an injection molding machine according to claim 1, characterized in that: An anti-slip layer is arranged on the contact surface of the fixing band (21) close to the convex ring (1).

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