A new digital sensor for injection molding machines

Abstract

This utility model discloses a novel digital sensor for injection molding machines, comprising a connecting rod, a strain gauge, a flexible PCB, and a digital amplifier. The connecting rod has a first connecting portion and a second connecting portion at its two ends along its length. An elastic strain zone is provided on the connecting rod, and a cover is detachably provided on the elastic strain zone. The first connecting portion, the second connecting portion, and the cover are cylindrical structures. An oblong hole is formed in the elastic strain zone. The strain gauge is attached to the upper and lower surfaces of the elastic strain zone. The flexible PCB is electrically connected to the output end of the strain gauge, and the digital amplifier is electrically connected to the output end of the flexible PCB. This utility model designs the connecting rod of the injection molding machine as a connecting rod with a built-in high-precision strain gauge force sensor. It can monitor the force on the connecting rod without the need for an external sensor, allowing the control system to monitor the clamping force of the injection molding machine in real time, ensuring that the mold can close tightly, thereby guaranteeing the shape and dimensional accuracy of the product.

Description

Technical Field

[0001] This utility model belongs to the field of sensor technology, specifically relating to a novel digital sensor for injection molding machines. Background Technology

[0002] Injection molding machines are commonly used equipment in plastic molding processes. Their working principle involves heating and melting plastic raw materials, then injecting them into a mold. Pressure is applied and the material is cooled and solidified to obtain the desired plastic product. One important performance parameter of injection molding machines is the clamping force. Clamping force (also called mold locking force) refers to the maximum clamping force in the clamping device that binds the male and female molds together to form a cavity for the product. When the raw material enters the cavity of the male and female molds with a certain injection force and speed, this clamping force prevents the mold from expanding due to the injection force of the raw material, thus ensuring the shape and dimensional accuracy of the product.

[0003] In existing technologies, monitoring the clamping force of an injection molding machine involves installing a force sensor on a connecting rod, which then transmits the clamping force to the sensor. However, the installation location and method of the force sensor are highly demanding and inconvenient.

[0004] Therefore, a new type of digital sensor for injection molding machines that is easy to install is urgently needed. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a novel digital sensor for injection molding machines.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0007] This utility model provides a novel digital sensor for injection molding machines, including a connecting rod, a strain gauge, a flexible PCB, and a digital amplifier. The connecting rod has a first connecting portion and a second connecting portion at its two ends along its length. An elastic strain zone is provided on the connecting rod between the first and second connecting portions. A cover is detachably provided on the elastic strain zone. The first connecting portion, the second connecting portion, and the cover are cylindrical structures. An installation groove is provided between the upper and lower surfaces of the elastic strain zone and the cover. A waist-shaped hole is formed on the elastic strain zone, penetrating both the upper and lower surfaces. The strain gauge is attached to the upper and lower surfaces of the elastic strain zone. The flexible PCB is sleeved on the connecting rod, and its input end is electrically connected to the output end of the strain gauge. The digital amplifier is disposed in the installation groove, and its input end is electrically connected to the output end of the flexible PCB.

[0008] Preferably, the cover includes an upper cover and a lower cover, the sides of the upper cover and the lower cover are semi-annular structures, and the upper cover and the lower cover respectively cover the upper surface and the lower surface of the elastic strain zone.

[0009] Preferably, the first or second connecting part is provided with a wire-passing oblique hole, which is provided to pass through the first or second connecting part along the length direction of the first or second connecting part, and one end of the wire-passing oblique hole is connected to the mounting groove.

[0010] Preferably, there are four waist-shaped holes, which are arranged in a square pattern. The strain gauges on the upper and lower surfaces of the elastic strain zone are arranged between the four waist-shaped holes in a cross pattern.

[0011] Preferably, a positive bridge arm is formed between the strain gauge on the upper surface of the elastic strain region located to the left of the cross and the strain gauge on the lower surface of the elastic strain region located to the right of the cross, and between the strain gauge on the upper surface of the elastic strain region located to the right of the cross and the strain gauge on the lower surface of the elastic strain region located to the left of the cross. A negative bridge arm is formed between the strain gauge on the upper surface of the elastic strain region located above the cross and the strain gauge on the lower surface of the elastic strain region located above the cross, and between the strain gauge on the upper surface of the elastic strain region located below the cross and the strain gauge on the lower surface of the elastic strain region located below the cross.

[0012] Preferably, a screw hole is provided on the upper or lower surface of the elastic strain zone, and the digital amplifier is disposed in the mounting groove by screws and screw holes.

[0013] Preferably, the outer end faces of the first connecting part and the second connecting part are provided with connecting threads, and the end faces of the first connecting part and the second connecting part near the strain zone of the elastic body are provided with bosses for installing the cover.

[0014] Compared with the prior art, this utility model has the following advantages:

[0015] This invention designs the connecting rod of the injection molding machine as a connecting rod with a built-in strain-type high-precision force sensor. It can monitor the force on the connecting rod without the need for external sensor installation, so that the control system can monitor the clamping force of the injection molding machine in real time, so as to ensure that the mold can be tightly closed, thereby ensuring the shape and dimensional accuracy of the product. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of a novel digital sensor for injection molding machines according to this utility model;

[0017] Figure 2 This is a schematic diagram of the structure of the elastic strain zone in a novel digital sensor for injection molding machines according to this utility model. Detailed Implementation

[0018] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0019] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0020] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Example 1

[0021] like Figures 1 to 2 As shown, this embodiment provides a novel digital sensor for injection molding machines, including a connecting rod, a strain gauge 4, a flexible PCB 5, and a digital amplifier 6.

[0022] In this embodiment, a first connecting part 1 and a second connecting part 2 are respectively provided at both ends of the connecting rod along its length. An elastic strain zone 3 is provided on the connecting rod and between the first connecting part 1 and the second connecting part 2. A cover 7 is detachably provided on the elastic strain zone 3. The first connecting part 1, the second connecting part 2, and the cover 7 are cylindrical structures. The cover 7 includes an upper cover and a lower cover. The sides of the upper cover and the lower cover are semi-annular structures. The upper cover and the lower cover respectively cover the upper surface and the lower surface of the elastic strain zone 3.

[0023] The first connecting part 1 is provided with a wire-passing oblique hole, which is provided to pass through the first connecting part 1 along the length direction of the first connecting part 1 or the second connecting part 2, and one end of the wire-passing oblique hole is connected to the mounting groove.

[0024] The outer end faces of the first connecting part 1 and the second connecting part 2 are provided with connecting threads, and the end faces of the first connecting part 1 and the second connecting part 2 near the strain zone of the elastic body are provided with bosses for installing the cover.

[0025] In this embodiment, an installation groove is provided between the upper and lower surfaces of the elastic strain zone 3 and the cover 6. Four waist-shaped holes 31 are provided on the elastic strain zone 3, which penetrate the upper and lower surfaces of the elastic strain zone. The waist-shaped holes 31 are arranged in a square shape. The strain gauges 4 are attached to the upper and lower surfaces of the elastic strain zone 3. The strain gauges 4 on the upper and lower surfaces of the elastic strain zone 3 are arranged between the four waist-shaped holes 31 and are arranged in a cross shape. Specifically, a positive bridge arm is formed between the strain gauge 4 located to the left of the cross on the upper surface of the elastic strain region 3 and the strain gauge 4 located to the right of the cross on the lower surface of the elastic strain region 3, and between the strain gauge 4 located to the right of the cross on the upper surface of the elastic strain region 3 and the strain gauge 4 located to the left of the cross on the lower surface of the elastic strain region 3. A negative bridge arm is formed between the strain gauge 4 located above the cross on the upper surface of the elastic strain region 3 and the strain gauge 4 located above the cross on the lower surface of the elastic strain region 3, and between the strain gauge 4 located below the cross on the upper surface of the elastic strain region 3 and the strain gauge 4 located below the cross on the lower surface of the elastic strain region 3. The positive and negative bridge arms constitute a strain-type high-precision force sensor.

[0026] In this embodiment, the flexible PCB 5 is sleeved on the connecting rod and its input end is electrically connected to the output end of the strain gauge 4. The upper surface of the elastic strain zone 3 is provided with screw holes. The digital amplifier 6 is set in the mounting groove through screws and screw holes and its input end is electrically connected to the output end of the flexible PCB 5.

[0027] The waist-shaped hole design of the elastic strain zone ensures equal positive and negative strain, improving product accuracy. This bridge arm design does not require high precision in patch positioning, effectively reducing errors caused by off-center or eccentric loads, thereby improving sensor accuracy. The built-in digital amplifier adds self-diagnostic function, and can output diagnostic signals if a bridge circuit short circuit or open circuit occurs, facilitating signal processing by the host computer.

[0028] The working principle of this embodiment will be further explained below:

[0029] The connecting rod is installed on the injection molding machine through threads at both ends. When the mold is closed, the connecting rod is stretched, that is, the sensor is stretched by an external force. The strain zone of the elastic body is deformed by the force, which causes the strain gauge to deform. As a result, the resistance of the strain gauge changes, which is converted into a voltage change by the bridge circuit. The digital amplifier converts the voltage output into a force value output.

[0030] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A novel digital sensor for injection molding machines, characterized in that, The device includes a connecting rod, a strain gauge (4), a flexible PCB (5), and a digital amplifier (6). The connecting rod has a first connecting part (1) and a second connecting part (2) at both ends along its length. An elastic strain zone (3) is provided on the connecting rod and between the first connecting part (1) and the second connecting part (2). A cover (7) is detachably provided on the elastic strain zone (3). The first connecting part (1), the second connecting part (2), and the cover (7) are cylindrical structures. An installation groove is provided between the upper and lower surfaces of the elastic strain zone (3) and the cover (6). A waist-shaped hole (31) is opened on the elastic strain zone (3) that passes through the upper and lower surfaces of the elastic strain zone. The strain gauge (4) is attached to the upper and lower surfaces of the elastic strain zone (3). The flexible PCB (5) is sleeved on the connecting rod and its input end is electrically connected to the output end of the strain gauge (4). The digital amplifier (6) is set in the installation groove and its input end is electrically connected to the output end of the flexible PCB (5).

2. The novel digital sensor for injection molding machines according to claim 1, characterized in that, The cover (7) includes an upper cover and a lower cover. The sides of the upper cover and the lower cover are semi-annular structures. The upper cover and the lower cover respectively cover the upper surface and the lower surface of the elastic strain zone (3).

3. The novel digital sensor for injection molding machines according to claim 1, characterized in that, The first connecting part (1) or the second connecting part (2) is provided with a wire-passing oblique hole. The wire-passing oblique hole is provided to pass through the first connecting part (1) or the second connecting part (2) along the length direction of the first connecting part (1) or the second connecting part (2). One end of the wire-passing oblique hole is connected to the mounting groove.

4. A novel digital sensor for injection molding machines according to claim 1, characterized in that, There are four waist-shaped holes (31), which are arranged in a square shape. The strain gauges (4) on the upper and lower surfaces of the elastic strain zone (3) are arranged between the four waist-shaped holes (31) in a cross shape.

5. A novel digital sensor for injection molding machines according to claim 4, characterized in that, The strain gauge (4) on the upper surface of the elastic strain region (3) located to the left of the cross and the strain gauge (4) on the lower surface of the elastic strain region (3) located to the right of the cross, and the strain gauge (4) on the upper surface of the elastic strain region (3) located to the right of the cross and the strain gauge (4) on the lower surface of the elastic strain region (3) located to the left of the cross respectively form a positive bridge arm. The strain gauge (4) on the upper surface of the elastic strain region (3) located above the cross and the strain gauge (4) on the lower surface of the elastic strain region (3) located above the cross, and the strain gauge (4) on the upper surface of the elastic strain region (3) located below the cross and the strain gauge (4) on the lower surface of the elastic strain region (3) located below the cross respectively form a negative bridge arm.

6. A novel digital sensor for injection molding machines according to claim 1, characterized in that, Screw holes are provided on the upper or lower surface of the elastic strain zone (3), and the digital amplifier (6) is installed in the mounting groove by screws and screw holes.

7. A novel digital sensor for injection molding machines according to claim 1, characterized in that, The first connecting part (1) and the second connecting part (2) are provided with connecting threads on their outer end faces, and the first connecting part (1) and the second connecting part (2) are provided with bosses for installing the cover on their end faces near the strain zone of the elastic body.

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