Safety protection device and protection method thereof

Abstract

The invention discloses a safety protection device and a protection method thereof.The device comprises a protection gate assembly and a bumper bar, the protection gate assembly comprises a gate, the bumper bar penetrates through a through hole of the gate, the through hole is provided with a one-way contact passing area and a non-contact passing area, and when a safety gate is closed, the bumper bar moves front and back through the non-contact passing area; when the safety door is opened, the one-way contact passing area clamps the bumper, and when the safety door is opened and the injection molding machine opens a mold, the bumper moves in a one-way mode in the mold opening direction through the one-way contact passing area. According to the protection method, when the safety door is closed, the bumper moves back and forth through the non-contact passing area. And when the safety door is opened, the one-way contact passing area clamps the bumper, and the injection molding machine stops moving. And when the safety door is opened and the mold is opened, the bumper moves unidirectionally along the mold opening direction through the one-way contact passing area, so that the injection molding machine can only open the mold but not close the mold when the safety door is opened.

Description

Technical Field

[0001] The invention belongs to the field of injection molding machines, and in particular relates to a safety protection device and a protection method thereof. Background Art

[0002] Injection molding machine is a main molding equipment that uses plastic molding molds to make plastic products of various shapes from thermoplastics or thermosetting materials. Injection molding machines are equipped with safety doors. Its function is to prevent the injection molding machine from closing the mold after the safety door is opened, thus protecting the personal safety of the operator.

[0003] Chinese patent CN221339466U discloses a mechanical safety device for an injection molding machine, which drives the mechanical safety gate to move up and down through a swing mechanism. When the safety door is opened, the mechanical safety gate clamps the mechanical safety rod, thereby locking the two clamping plates and stopping the movement of the two clamping plates.

[0004] In actual use, when the safety door is opened and the second clamping plate stops moving, sometimes the second clamping plate needs to be able to open the mold with the door open. On the one hand, it is convenient for operators to find out the cause of machine failure, and on the other hand, it is to prevent the material in the mold from solidifying and hardening, which will cause the subsequent mold to be unable to be opened and damage the mold. However, the mechanical safety device disclosed in Chinese patent CN221339466U can only stop the movement of the second clamping plate after the safety door is opened, and cannot open the second clamping plate, so the operation is inconvenient. Summary of the invention

[0005] The purpose of the present invention is to provide a safety protection device and a protection method thereof. The protection gate assembly is provided with a one-way contact passing area. When the gate is stuck on the safety rod, the two locking plates can be opened smoothly but cannot be closed, and the operation is convenient.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] The safety protection device is installed on one side of the locking assembly of the injection molding machine and close to the safety door, and includes a protective gate assembly and a safety rod. The protective gate assembly includes a gate. The safety rod passes through the through hole of the gate. The through hole is provided with a one-way contact passing area and a non-contact passing area. When the safety door is closed, the safety rod moves back and forth through the non-contact passing area. When the safety door is opened, the one-way contact passing area clamps the safety rod. When the safety door is open, when the injection molding machine opens the mold, the safety rod moves one-way along the mold opening direction through the one-way contact passing area.

[0008] Since the through hole on the gate is provided with a one-way contact passing area and a non-contact passing area, when the safety door is closed, the gate remains in the highest position, and when the injection molding machine opens and closes the mold, the thrust assembly drives the safety rod to move forward and backward from the non-contact passing area. When the safety door is opened, the one-way contact passing area jams the safety rod, and the injection molding machine stops working. If the mold needs to be opened, the safety rod can pass through the one-way contact passing area along the mold opening direction, but cannot pass through the one-way contact passing area along the mold closing direction, so that the injection molding machine can only open the mold but not close the mold when the safety door is opened.

[0009] Furthermore, the mold locking assembly includes two mold locking plates, a thrust assembly, a machine hinge structure and a mold locking tail plate. The two mold locking plates and the mold locking tail plate are connected by a machine hinge structure. The thrust assembly pushes the two mold locking plates to open or close the mold. The safety protection device also includes a protection connecting rod assembly. The protection connecting rod assembly is connected to the protection gate assembly. The protection connecting rod assembly drives the gate to move up and down. The safety rod is fixed to the thrust assembly, and the protection gate assembly is fixed to the mold locking tail plate.

[0010] The thrust assembly drives the two clamping plates to move forward and backward through the hinge structure to open and close the mold of the injection molding machine. The protective connecting rod assembly drives the gate to move up and down to tighten and loosen the gate to the protective rod.

[0011] Furthermore, the protective gate assembly also includes a gate fixing frame, which is fixed to the locking assembly. The gate is fixedly connected to one end of the protective connecting rod assembly. The gate fixing frame is provided with a limit groove, and the gate moves up and down in the limit groove. The gate fixing frame is provided with a circular hole, and the gate is provided with a through hole, and the safety rod passes through the through hole and the circular hole.

[0012] The gate moves up and down in the limit groove of the gate fixing frame, limiting the position of the gate so that it can be aligned with the safety rod. The round hole is usually larger than the through hole so that the safety rod can pass through the round hole smoothly.

[0013] Furthermore, the bumper includes a bumper body and a raised portion, the bumper body forms a trough area, the raised portion is provided with a climbing area and a crest area, the radii of the trough area and the crest area remain unchanged, and the radius of the climbing area gradually increases.

[0014] The raised part matches with the gate through hole. The setting of the climbing area of ​​the raised part can make the gate gradually lift upward, so that the safety rod can pass through the through hole in one direction. The wave crest area of ​​the raised part is used to abut against the outer periphery of the through hole, so that the safety rod cannot move along the mold closing direction, and the two clamping plates cannot close the mold.

[0015] Furthermore, the through hole includes an upper through hole and a lower through hole that are connected. The upper through hole and the lower through hole form an asymmetric gourd-shaped through hole. The upper through hole is a one-way contact passing area, and the lower through hole is a non-contact passing area. When the gate moves downward, the upper through hole clamps the safety rod.

[0016] The gate is moved up and down to switch the upper through hole and the lower through hole, so as to realize the clamping and loosening of the safety rod.

[0017] Furthermore, the side of the gate away from the clamping assembly is the A side, the side of the gate close to the clamping assembly is the B side, the radius of the upper through hole on the A side is R1, the radius of the upper through hole on the B side is R2, the radius of the lower through hole is R3, the radius of the peak area is R4, R1 <R4<R2=R3。

[0018] The radius of the upper through hole on the B side is larger than that on the A side, thereby achieving a one-way contact passing effect. The radius of the lower through hole is larger than the radius of the wave crest area of ​​the bumper, thereby allowing the bumper to move smoothly in the lower through hole without contact.

[0019] Furthermore, the upper through hole is provided with two symmetrically arranged oblique arc surfaces, which are funnel-shaped, and the width of the oblique arc surfaces gradually increases from surface A to surface B. The inclination angle α of the oblique arc surfaces is greater than the inclination angle β of the climbing zone. The oblique arc surfaces are formed by a truncated cone tangent to the top of the upper through hole, and an upper intersection line and a lower intersection line are generated after the truncated cone is tangent to the upper through hole. The upper intersection line is an arc line protruding into the upward through hole, and the upper intersection line is in point contact with the climbing zone.

[0020] When the safety door is opened, the safety rod extends and rubs against the gate continuously, causing the parts to wear each other and the safety rod to pass unsmoothly. In order to reduce the degree of wear between the safety rod and the gate, a funnel-shaped oblique arc surface is designed, and the radius of the oblique arc surface on the B surface is the same as the radius of the lower through hole. The oblique arc surface is symmetrically arranged on the inner side of the upper through hole.

[0021] The gate may get stuck in the trough area, climbing area and crest area of ​​the safety bar, and the inclination angle of the oblique arc surface is slightly larger than the inclination angle of the climbing area, so that when the gate gets stuck in the climbing area of ​​the safety bar, the oblique arc surface can wrap the climbing area well.

[0022] The oblique arc surface is obtained by the intersection of the calabash hole with the same diameter of the upper through hole and the lower through hole and the truncated cone. Due to the special structure of the oblique arc surface, when the climbing area passes through the upper through hole, only the upper intersection line contacts the climbing area. And because the upper intersection line is an arc protruding inward, the upper intersection line and the climbing area are point contact. Compared with surface contact and point contact, point contact has the smallest contact area and the smallest friction force. Therefore, the climbing area can smoothly pass through the upper through hole, thereby greatly improving the life of the bumper.

[0023] In order to reduce friction, the climbing area has a relatively gentle inclination angle in the horizontal direction, preferably 10°-30°. The difference between the inclination angle of the oblique arc surface and the inclination angle of the climbing area is preferably 0-5°.

[0024] Furthermore, the truncated cone is formed by rotating a right-angled trapezoid along the right-angled side. The upper base of the right-angled trapezoid is R5, the lower base of the right-angled trapezoid is R6, the right-angled side of the right-angled trapezoid is H1, the angle between the waist H2 of the right-angled trapezoid and the right-angled side H1 is γ, the right-angled side H1 is parallel to the central axis of the upper through hole, and R5 <R6=R4,γ<β。

[0025] The upper base R5 of the right-angled trapezoid is smaller than the lower base R6 of the right-angled trapezoid, and the lower base R6 of the right-angled trapezoid is the same as the radius R4 of the lower through hole. The angle γ between the waist and the right-angled side of the right-angled trapezoid is smaller than the inclination angle β of the bumper climbing area. The upper intersection line obtained by the intersection of the truncated cone and the upper through hole that meets the above conditions can achieve point contact with the climbing area.

[0026] Furthermore, limit blocks are provided at the upper and lower ends of the A surface of the gate, and chamfers are provided on the B surface of the lower through hole.

[0027] The limit block limits the highest and lowest positions of the gate on the gate fixing frame.

[0028] A protection method using a safety protection device comprises the following steps:

[0029] 1. The safety door is closed, the protective connecting rod assembly keeps the gate in the highest position, the thrust assembly drives the second clamping plate to move forward and backward, the safety bar moves forward and backward from the non-contact passing area, and the injection molding machine operates normally;

[0030] 2. The safety door is opened, the protective connecting rod assembly drives the gate to move downward, the one-way contact passing area blocks the safety rod, the crest area cannot extend through the one-way contact passing area along the mold closing direction, and the second clamping plate cannot close the mold;

[0031] 3. When the safety door is open, the mold is opened, and the second clamping plate moves toward the clamping tail plate, driving the safety rod to extend unidirectionally along the mold opening direction through the one-way contact passing area, and the second clamping plate opens.

[0032] Since the gate through hole has an oblique arc surface with a special structure, the safety rod can be extended in one direction along the mold opening direction but cannot be extended in the mold closing direction when the safety door is opened.

[0033] Further, in step 3, the specific steps of the bumper passing through the one-way contact area are as follows:

[0034] 3.1 One-way contact through area contacts the trough area, the trough area is a horizontal area, and the bumper passes directly;

[0035] 3.2 The one-way contact passing area contacts the climbing area. The one-way contact passing area and the climbing area are in point contact, and the safety bar gradually lifts the gate upwards;

[0036] 3.3 One-way contact through area Contact crest area, the safety bar lifts the gate to the highest point, the crest area is a horizontal area, and the safety bar passes directly.

[0037] When the bumper passes through the one-way contact passing area of ​​the through hole, it passes through the trough area, the climbing area and the crest area.

[0038] Since the radius of the trough area is smaller than the radius of the upper through hole on the A surface, the trough area can smoothly pass through the one-way contact passing area.

[0039] The climbing area is in point contact with the upper intersection line of the oblique arc surface, and the friction force is very small, so it can smoothly pass through the one-way contact passing area and gradually lift the gate upward.

[0040] When the climbing area lifts the gate to the highest point, since the radius of the crest area is the same as the radius of the upper through hole on the B surface, the crest area can also pass through the area through one-way contact.

[0041] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0042] 1. Since the through hole on the gate is provided with a one-way contact passing area and a non-contact passing area, when the safety door is closed, the protective connecting rod assembly keeps the gate in the highest position, and when the second clamping plate opens and closes the mold, the thrust assembly drives the safety rod to move forward and backward from the non-contact passing area. When the safety door is opened, the protective connecting rod assembly drives the gate to move downward, so that the one-way contact passing area jams the safety rod, and the second clamping plate stops working. If the mold needs to be opened, the second clamping plate moves toward the clamping tail plate, and the safety rod can pass through the one-way contact passing area along the mold opening direction, but cannot pass through the one-way contact passing area along the mold closing direction, so that the second clamping plate can only open the mold but not close the mold when the safety door is opened.

[0043] 2. The one-way contact passing area is provided with an oblique arc surface, so that when the climbing area passes through the upper through hole, only the upper intersection line contacts the climbing area. And because the upper intersection line is an arc protruding inward, the upper intersection line and the climbing area are in point contact. Compared with surface contact and point contact, point contact has the smallest contact area and the smallest friction force. Therefore, the climbing area can pass through the upper through hole smoothly, thereby greatly improving the life of the bumper. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention will be further described below by means of the accompanying drawings.

[0045] Figure 1 This is a schematic diagram of the structure of an injection molding machine.

[0046] Figure 2 This is a schematic diagram of the structure of the injection molding machine after removing the clamping tail plate and safety door.

[0047] Figure 3It is a schematic diagram of the structure of the safety protection device when the safety door is closed.

[0048] Figure 4 This is a schematic diagram of the structure of the safety protection device when the safety door is open.

[0049] Figure 5 This is a schematic diagram of the gate structure.

[0050] Figure 6 This is the front view of the gate.

[0051] Figure 7 This is the back view of the gate.

[0052] Figure 8 This is a cross-sectional view of the gate.

[0053] Fig. 9 Schematic diagram of the intersection of the gate and the cone.

[0054] Fig.10 for Fig. 9 Schematic diagram of the other direction.

[0055] Fig.11 It is a side view of a right trapezoid.

[0056] Fig.12 This is a cross-sectional view of the trough area passing through the gate when the safety rod moves along the mold opening direction.

[0057] Fig.13 It is a cross-sectional view of the climbing area passing through the gate when the safety rod moves along the mold opening direction.

[0058] Fig.14 This is a cross-sectional view of the wave crest area passing through the gate when the safety rod moves along the mold opening direction. DETAILED DESCRIPTION

[0059] like Figure 1 The injection molding machine shown is provided with a mold locking assembly and a safety protection device, wherein the safety protection device is installed on one side of the mold locking assembly of the injection molding machine and close to the safety door 1 .

[0060] like Figure 2 The clamping assembly shown includes a clamping plate 2, a thrust seat 3, a clamping cylinder 4, a hinge structure 5 and a clamping tail plate 6. The clamping plate 2 and the clamping tail plate 6 are connected by the hinge structure 5. The thrust assembly includes: the clamping cylinder 4 is fixed to the clamping tail plate 6, the piston rod 33 of the clamping cylinder 4 is fixed to the thrust seat 3, the clamping cylinder 4 pushes the thrust seat 3 to move forward and backward, the thrust seat 3 and the clamping plate 2 are connected by the hinge structure 5, and the thrust seat 3 moves the clamping plate 2 forward and backward to open or close the mold.

[0061] like Figure 1 , Figure 3 and Figure 4The safety protection device comprises a protection connecting rod assembly 7, a protection gate assembly 8 and a safety rod 9, and the safety rod 9 is fixed to the thrust seat 3.

[0062] The protective gate assembly 8 includes a gate 81 and a gate fixing frame 82. The gate fixing frame 82 is fixed to the clamping tail plate 6. The gate 81 is fixedly connected to one end of the protective connecting rod assembly 7. The gate fixing frame 82 is provided with a limit groove (not shown in the figure). The gate 81 moves up and down in the limit groove. The gate fixing frame 82 is provided with a circular hole 83. The gate 81 is provided with a through hole 84. The safety rod 9 passes through the through hole 84 and the circular hole 83. The circular hole 83 is usually larger than the through hole 84, so that the safety rod 9 can pass through the circular hole 83 smoothly.

[0063] The protective link assembly 7 includes an axle 71, a rocker 72 and a swing arm 73. A bearing 74 with a certain weight is provided on one side of the axle 71, and a rocker 72 is provided on the other side of the axle 71. The rocker 72 is connected to one end of the swing arm 73, and the other end of the swing arm 73 is fixed to the bottom of the gate 81. The swing arm 73 is in a Z shape.

[0064] A safety door pressing plate 10 is fixed to the back of the safety door 1 , and the safety door pressing plate 10 moves forward and backward as the safety door 1 is opened and closed.

[0065] like Figure 3 As shown, when the safety door 1 is closed, the safety door pressing plate 10 moves to the bottom of the bearing 74 and lifts the bearing 74 upward, the rocker 72 rotates downward, the swing rod 73 rotates clockwise, and the gate 81 is lifted upward. After the safety door 1 remains closed, the gate 81 remains in the highest position.

[0066] like Figure 4 As shown, when the safety door 1 is opened, the safety door pressure plate 10 moves away from the bearing 74, the bearing 74 rotates downward under the action of gravity, the rocker 72 is lifted upward, the swing rod 73 rotates counterclockwise, the gate 81 clamps the safety rod 9 downward, the thrust seat 3 stops moving, and the second clamping plate 2 stops moving.

[0067] like Figure 3 , Figure 4 , Figure 12-14 As shown, the bumper 9 includes a bumper body and a raised portion. The bumper body forms a trough area 91, and the raised portion is provided with a climbing area 92 and a crest area 93. The radii of the trough area 91 and the crest area 93 remain unchanged, and the radius of the climbing area 92 gradually increases.

[0068] like Figure 5-Figure 8 As shown, the through hole 84 includes an upper through hole 85 and a lower through hole 86 which are connected. The upper through hole 85 and the lower through hole 86 constitute an asymmetric gourd-shaped through hole. The upper through hole 85 is a one-way contact passing area, and the lower through hole 86 is a non-contact passing area. When the gate 81 moves downward, the upper through hole 85 clamps the safety rod 9.

[0069] One side of the gate 81 away from the die clamping tail plate 6 is the A side, as Figure 6 shown. One side of the gate 81 close to the die clamping tail plate 6 is the B side, as Figure 7 shown. The radius of the upper through hole 85 on the A side is R1, the radius of the upper through hole 85 on the B side is R2, and the radius of the lower through hole 86 is R3, as Fig.12 shown. The radius of the wave crest area 93 is R4, and R1 < R4 < R2 = R3. Limit blocks 87 are provided at the upper and lower ends of the A side of the gate 81, and a chamfer 88 is provided for the lower through hole 86 on the B side.

[0070] As Figure 5 and Figure 6 shown, the upper through hole 85 is provided with two symmetrically arranged oblique arc surfaces 89. The oblique arc surface 89 is in a funnel shape, and the width of the oblique arc surface 89 gradually increases from the A side to the B side.

[0071] As Fig. 9 and Fig.10 shown, the oblique arc surface 89 is formed by the upper through hole 85 and the lower through hole 86 with unchanged diameters being tangent to the frustum 13.

[0072] The frustum 13 is formed by rotating a right trapezoid 14 around the right-angled side H1 for one circle, as Fig.11 shown. The upper base of the right trapezoid 14 is R5, the lower base of the right trapezoid 14 is R6, the right-angled side of the right trapezoid 14 is H1, the included angle between the waist H2 of the right trapezoid 14 and the right-angled side H1 is γ, the right-angled side H1 is parallel to the central axis of the upper through hole 85, R5 < R6 = R4, and γ < β.

[0073] After the frustum 13 is tangent to the upper through hole 85, an upper intersection line 11 and a lower intersection line 12 are generated. The upper intersection line 11 is an arc protruding into the upper through hole 85, and the upper intersection line 11 is in point contact with the climbing area 92.

[0074] Figure 8 In , the intersection points of the upper intersection line 11 on the A side and the B side are a and b respectively. Connect the two points a and b with a dotted line. Compared with the ab connection line, it can be seen that the contour of the upper intersection line 11 is an arc protruding towards the climbing area 92.

[0075] In this embodiment, the included angle between the ab dotted line and the central axis of the upper through hole 85 is used as the inclination angle α of the oblique arc surface 89. The inclination angle α of the oblique arc surface 89 is 28°, the inclination angle β of the climbing area 92 in the horizontal direction is 25°, and the included angle γ between the waist H2 of the right trapezoid 14 and the right-angled side H1 is 12°.

[0076] A protection method using a safety protection device includes the following steps:

[0077] 1. As Figure 2As shown, the safety door 1 is closed, the protective connecting rod assembly 7 keeps the gate 81 at the highest position, the piston rod of the clamping cylinder 4 drives the thrust seat 3 to move forward and backward, and drives the clamping second plate 2 to move forward and backward through the hinge structure 5, the safety bar 9 moves forward and backward from the non-contact passing area, and the injection molding machine operates normally;

[0078] 2. If Figure 3 As shown, the safety door 1 is opened, the protective connecting rod assembly 7 drives the gate 81 to move downward, the one-way contact passing area blocks the safety rod 9, the peak area 93 cannot extend through the one-way contact passing area along the mold closing direction, and the second clamping plate 2 cannot close the mold;

[0079] 3. When the safety door 1 is open, the mold is opened, and the thrust seat 3 moves along the mold opening direction, driving the safety rod 9 to extend unidirectionally along the mold opening direction through the unidirectional contact passing area, and the second clamping plate 2 is opened. The specific steps are as follows:

[0080] 3.1 As Fig.12 As shown, the one-way contact passing area contacts the trough area 91, and the trough area 91 is a horizontal area, and the bumper 9 passes directly;

[0081] 3.2 As Fig.13 As shown, the one-way contact passing area contacts the climbing area 92, the one-way contact passing area and the climbing area 92 are in point contact, and the safety rod 9 gradually lifts the gate 81 upward;

[0082] 3.3 As Fig.14 As shown, the one-way contact passing area contacts the crest area 93, the safety bar 9 lifts the gate 81 to the highest point, the crest area 93 is a horizontal area, and the safety bar 9 passes directly.

[0083] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent replacements or modifications made based on the present invention to solve basically the same technical problems and achieve basically the same technical effects are all included in the protection scope of the present invention.

Claims

1. The safety protection device is installed on one side of the mold clamping assembly of the injection molding machine and close to the safety door, and is characterized by: The invention comprises a protective gate assembly and a safety rod, wherein the protective gate assembly comprises a gate, the safety rod passes through a through hole of the gate, the through hole is provided with a one-way contact passing area and a non-contact passing area, when the safety gate is closed, the safety rod moves forward and backward through the non-contact passing area, when the safety gate is opened, the one-way contact passing area clamps the safety rod, and when the injection molding machine opens the mold while the safety gate is in the open state, the safety rod moves one-way along the mold opening direction through the one-way contact passing area.

2. The safety protection device according to claim 1, characterized in that: The clamping assembly includes two clamping plates, a thrust assembly, a machine hinge structure and a clamping tail plate. The two clamping plates and the clamping tail plate are connected via the machine hinge structure. The thrust assembly pushes the two clamping plates to open or close the mold. The safety protection device also includes a protection connecting rod assembly, which is connected to the protection gate assembly. The safety rod is fixed to the thrust assembly, and the protection gate assembly is fixed to the clamping tail plate.

3. The safety protection device according to claim 1, characterized in that: The protective gate assembly also includes a gate fixing frame, which is fixed to the locking assembly. The gate is fixedly connected to one end of the protective connecting rod assembly. The gate fixing frame is provided with a limiting groove. The gate moves up and down in the limiting groove. The gate fixing frame is provided with a circular hole. The gate is provided with a through hole. The safety rod passes through the through hole and the circular hole.

4. The safety protection device according to claim 1, characterized in that: The bumper comprises a bumper body and a raised portion, wherein the bumper body forms a trough area, and the raised portion is provided with a climbing area and a crest area, wherein the radii of the trough area and the crest area are constant, and the radius of the climbing area gradually increases.

5. The safety protection device according to claim 3, characterized in that: The through hole includes an upper through hole and a lower through hole that are connected, and the upper through hole and the lower through hole constitute an asymmetric gourd-shaped through hole. The upper through hole is the one-way contact passing area, and the lower through hole is the non-contact passing area. When the gate moves downward, the upper through hole clamps the safety rod.

6. The safety protection device according to claim 4, characterized in that: The side of the gate away from the clamping assembly is surface A, the side of the gate close to the clamping assembly is surface B, the radius of the upper through hole on surface A is R1, the radius of the upper through hole on surface B is R2, the radius of the lower through hole is R3, the radius of the peak area is R4, R1 <R4<R2=R3。 7. The safety protection device according to claim 5, characterized in that: The upper through hole is provided with two symmetrically arranged oblique arc surfaces, the oblique arc surfaces are funnel-shaped, the width of the oblique arc surfaces gradually increases from the A surface to the B surface, the inclination angle α of the oblique arc surfaces is greater than the inclination angle β of the climbing zone, the oblique arc surfaces are formed by a truncated cone being tangent to the top of the upper through hole, and an upper intersection line and a lower intersection line are generated after the truncated cone is tangent to the upper through hole, the upper intersection line is an arc line protruding into the upper through hole, and the upper intersection line is in point contact with the climbing zone.

8. The safety protection device according to claim 6, characterized in that: The truncated cone is formed by rotating a right-angled trapezoid along a right-angled side. The upper base of the right-angled trapezoid is R5, the lower base of the right-angled trapezoid is R6, the right-angled side of the right-angled trapezoid is H1, and the waist H2 of the right-angled trapezoid is connected to the right-angled side H1. The angle between them is γ, the right angle side H1 is parallel to the central axis of the upper through hole, R5 <R6=R4,γ<β。 9. A protection method using the safety protection device according to any one of claims 1 to 8, characterized in that: The steps include:

1. The safety door is closed, the protective connecting rod assembly keeps the gate in the highest position, the thrust assembly drives the second clamping plate to move forward and backward, the safety bar moves forward and backward from the non-contact passing area, and the injection molding machine operates normally; 2. The safety door is opened, the protective connecting rod assembly drives the gate to move downward, the one-way contact passing area blocks the safety rod, the crest area cannot extend through the one-way contact passing area along the mold closing direction, and the second clamping plate cannot close the mold; 3. When the safety door is open, the mold is opened, and the second clamping plate moves toward the clamping tail plate, driving the safety rod to extend unidirectionally along the mold opening direction through the one-way contact passing area, and the second clamping plate opens.

10. The protection method of the full protection device according to claim 9, when the safety door is opened, is characterized in that: In step 3, the specific steps of the bumper passing through the one-way contact area are as follows: 3.1 One-way contact through area contacts the trough area, the trough area is a horizontal area, and the bumper passes directly; 3.2 The one-way contact passing area contacts the climbing area. The one-way contact passing area and the climbing area are in point contact, and the safety bar gradually lifts the gate upwards; 3.3 One-way contact through area Contact crest area, the safety bar lifts the gate to the highest point, the crest area is a horizontal area, and the safety bar passes directly.

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