A safety control device for initiating and isolating explosion test and a method of using the same

Abstract

The application discloses a safety control device for detonation and explosion-proof test and a use method thereof, and belongs to the technical field of fuze explosion-proof, which comprises a shell, a sliding block, an electromagnetic push pin device and an electromagnetic pull pin device. The shell is provided with a first accommodating groove corresponding to the sliding block to accommodate the sliding block and enable the sliding block to move in the first accommodating groove. The first accommodating groove is also connected with a first through hole and a second through hole. The output end of the electromagnetic push pin device extends into the first accommodating groove through the first through hole and is connected with the sliding block. The sliding block is provided with a plurality of grooves corresponding to the output end of the electromagnetic pull pin device. The side wall surface of the first accommodating groove away from the first through hole is provided with not less than four second accommodating grooves for respectively accommodating one metal piece. The two metal pieces are connected with a power supply and form at least two groups of circuits. The safety control device for detonation and explosion-proof test and the use method thereof have high overall safety, the operation method can be remotely realized, and the operation method has time sequence and high safety.

Description

Technical Field

[0001] This invention belongs to the field of explosion-proof fuse technology, specifically relating to a safety control device for detonation and explosion-proof testing and its usage method. Background Technology

[0002] Pyrotechnic devices are typically equipped with explosion-proof mechanisms, which isolate sensitive pyrotechnic elements in the detonation sequence from the next level of pyrotechnic elements. This ensures that if a sensitive pyrotechnic element is accidentally activated, it will not detonate the next level of pyrotechnic elements, thereby guaranteeing the safety of personnel and equipment during service operations.

[0003] To verify the correctness of the fuse's detonation sequence design, initiation and explosion-proof tests are required. Because the fuse's detonation sequence contains a large amount of explosive, to ensure operator safety during initiation and explosion-proof tests, the initial pyrotechnic device, typically an electric detonator, is usually remotely detonated via cable. Especially during initiation tests, to ensure personnel safety, the fuse safety is typically disengaged remotely before the electric detonator is remotely powered for detonation.

[0004] However, the safety of the above operations is not very high. There is a possibility that a power supply mis-triggering or failure to turn off the power could cause the entire circuit to be connected immediately upon connection, thus detonating the electric detonator and causing accidental injury. Currently, the regulation on the safety failure rate of fuses states: "Before the predetermined release of safety and release of isolation procedures begin: the failure rate to prevent the fuse from releasing isolation or functioning should not exceed one in a million." This demonstrates the importance placed on safe fuse operation. To improve operational safety, it is necessary to address the safety risks of fuse detonation tests and explosion-proof tests. Summary of the Invention

[0005] In response to one or more of the above-mentioned defects or improvement needs of the prior art, the present invention provides a safety control device and its usage method for detonation and explosion-proof testing, which can reduce the risk of accidental detonation of electric detonators that may occur when connecting the detonation circuit of the fuse.

[0006] To achieve the above objectives, the present invention provides a safety control device for detonation and explosion-proof testing, including a housing, a slider, an electromagnetic pusher, and an electromagnetic pin puller; the housing is provided with a first receiving groove corresponding to the slider to receive the slider and allow the slider to move within the first receiving groove; the first receiving groove is also connected to a first through hole and a second through hole;

[0007] The output end of the electromagnetic pusher extends into the first receiving groove through the first through hole and connects to the slider; thus enabling the slider to slide within the first receiving groove under the action of the electromagnetic pusher.

[0008] The slider is provided with multiple grooves corresponding to the output end of the electromagnetic pin puller, so that the output end of the electromagnetic pin puller extends into the first receiving groove through the second through hole and can be embedded in the groove.

[0009] The first receiving groove is provided with at least four second receiving grooves on the side wall opposite to the first through hole, for accommodating a metal part respectively; a power supply is connected between the two metal parts to form at least two sets of circuits, one set of circuits is also connected to an electric detonator, and the other set of circuits is also connected to an alarm; wherein, the slider is made of conductive material, and the housing is made of non-conductive material.

[0010] As a further improvement of the present invention, the metal part includes a connecting part and an inclined part, the inclined part and the connecting part are connected at a certain angle, the connecting part extends in a horizontal direction, and the inclined part extends into the first receiving groove.

[0011] As a further improvement of the present invention, the angle between the inclined portion and the horizontal direction is in the range of 20° to 45°.

[0012] As a further improvement of the present invention, a connector is also included, wherein a connecting hole is provided on the connecting portion, and the connector connects the metal part to the housing through the connecting hole.

[0013] As a further improvement of the present invention, the metal part further includes a fitting portion, which is perpendicular to the connecting portion and can fit the side wall of the housing.

[0014] As a further improvement of the present invention, the housing is also provided with a third receiving groove corresponding to the alarm to receive the alarm.

[0015] As a further improvement of the present invention, the output end of the electromagnetic pusher is provided with a thread, and the slider is provided with a corresponding threaded hole, and the two are connected by a thread.

[0016] As a further improvement of the present invention, a weight-reducing hole is provided at the bottom of the slider, and the groove on the slider communicates with the weight-reducing hole to form a third through hole.

[0017] As a further improvement of the present invention, the housing is made of a non-conductive material.

[0018] Another aspect of the present invention provides a method for using a safety control device for detonation and explosion-proof testing. The specific operating steps of using the safety control device for detonation and explosion-proof testing as described above are as follows:

[0019] (1) After the safety control device for the detonation and explosion-proof test is installed, the output end of the electromagnetic pin puller is inserted into the groove at the end of the slider away from the electromagnetic pin puller. Use a multimeter to check whether the circuit composed of the metal parts is in an open circuit state. After ensuring that it is in an open circuit state, use a power supply to power the electromagnetic pin puller. The electromagnetic pin puller is pulled back to release the constraint on the slider.

[0020] (2) After supplying power to the electromagnetic pin puller for 2s to 3s, the electromagnetic pusher is then supplied with power for 2s to 3s. The electromagnetic pusher pushes the slider to move and makes the slider contact the metal part.

[0021] (3) After the slider moves to the position, the electromagnetic pin puller is de-energized, the output end of the electromagnetic pin puller is inserted into another groove on the slider, the electromagnetic pin puller locks the slider, and the electromagnetic pusher is de-energized 2s to 3s after the electromagnetic pin puller is de-energized.

[0022] (4) Power the circuit connected to the alarm and check whether the alarm works. If the alarm works, it can be determined that the metal part is connected in place. Then stop powering the alarm and evacuate the personnel. Power the circuit connected to the electric detonator and check whether the detonation or explosion-proof test of the fuse meets the requirements.

[0023] The aforementioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0024] In summary, the beneficial effects of the above-described technical solutions conceived by this invention compared with the prior art include:

[0025] (1) The safety control device for detonation and explosion-proof testing of the present invention uses an electromagnetic pusher to drive a conductive slider, enabling the conductive slider to contact a metal part, thereby connecting the metal parts and forming a closed circuit. The electromagnetic puller engages with a groove on the slider, allowing the electromagnetic puller to lock or unlock the slider, improving the reliability of the device. The top cover provides protection and support for the electromagnetic pusher and the electromagnetic puller. The device has good overall safety, can be operated remotely, and will not detonate the electric detonator due to accidental power supply.

[0026] (2) The safety control device and its method for explosion-proof test of the present invention further limits the structure of the metal parts to ensure that the slider can contact the metal parts after sliding into place and can return to its natural state after the connection is completed, so that the device can be used multiple times and improve the applicability and accuracy of the device.

[0027] (3) The method of using the safety control device for detonation and explosion-proof testing of the present invention is simple and convenient to operate, and has a time sequence. Only by operating in the correct time sequence can the slider move into place and realize the switching of the position switch, which has a high safety.

[0028] (4) The safety control device and its usage method for detonation and explosion-proof testing in this invention have high overall safety. All operations can be performed remotely, and the alarm can be used to remotely check whether the slider has moved to the correct position to form a circuit between the metal parts. The device can be remotely controlled to switch the circuit from open to closed. The operation method is time-sensitive; only by operating according to the correct sequence can the slider move to the correct position, achieving the switching of the position switch, thus ensuring high safety. This device ensures operational safety and prevents the detonator from detonating due to accidental power supply. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the overall structure of the safety control device for detonation and explosion-proof testing in an embodiment of the present invention, in its initial state.

[0031] Figure 2 This is a schematic diagram of the overall structure of the safety control device for detonation and explosion-proof testing in an embodiment of the present invention, in the state of being in place.

[0032] Figure 3 This is a side view of the metal components of the safety control device for detonation and explosion-proof testing in an embodiment of the present invention;

[0033] Figure 4 This is a front view of the metal component of the safety control device for detonation and explosion-proof testing in an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the base of the safety control device for detonation and explosion-proof testing in an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the upper cover of the safety control device for detonation and explosion-proof testing in an embodiment of the present invention;

[0036] Figure 7 This is a schematic diagram of the safety control device for detonation and explosion-proof testing in an embodiment of the present invention;

[0037] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically:

[0038] 1. Base; 2. Electromagnetic pusher; 3. Electromagnetic pin puller; 4. Slider; 5. Metal parts; 6. Top cover; 7. Alarm;

[0039] 101. First through hole; 102. First receiving groove; 1021. Second receiving groove;

[0040] 501. Connecting part; 502. Inclined part; 503. Fitting part; 5011. Connecting hole;

[0041] A. The angle between the inclined part and the horizontal direction. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0043] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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 invention.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0045] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0047] Example:

[0048] Please see Figures 1 to 7 In a preferred embodiment of the present invention, a safety control device for detonation and explosion-proof testing is provided, comprising a housing, a slider 4, an electromagnetic pusher 2, and an electromagnetic pin puller 3. In the preferred embodiment, the housing consists of a base 1 and a top cover 6, connected by screws, such as... Figure 5 and Figure 6 As shown, threaded holes are provided at the four corners of the base 1 and the top cover 6, so that the top cover 6 can be connected to the base 1 by screws. The housing is made of non-conductive material.

[0049] Specifically, in a preferred embodiment, the housing is provided with a first receiving groove 102 corresponding to the slider 4 to accommodate the slider 4 and allow the slider 4 to move within the first receiving groove 102. The first receiving groove 102 is also connected to a first through hole 101 and a second through hole. The output end of the electromagnetic pusher 2 extends into the first receiving groove 102 through the first through hole 101 and connects with the slider 4, allowing the slider 4 to slide within the first receiving groove 102 under the action of the electromagnetic pusher 2. In a preferred embodiment, the output end of the electromagnetic pusher 2 is provided with a thread, and the slider 4 is provided with a corresponding threaded hole, and the two are threadedly connected. The electromagnetic pusher 2 is energized by a coil to realize the attraction movement of the armature and the yoke, thereby driving the push of the output pin of the electromagnetic pusher 2.

[0050] Furthermore, in a preferred embodiment, the slider 4 is provided with multiple grooves corresponding to the output end of the electromagnetic pin puller 3, so that the output end of the electromagnetic pin puller 3 extends into the first receiving groove 102 through the second through hole and can be embedded in the groove. It is understood that, as Figure 1 and Figure 2 As shown, there are two grooves. One is used to lock the slider 4 with the electromagnetic puller 3 in the initial state, and the other is used to lock the slider 4 with the electromagnetic puller 3 when the slider 4 is in place. The distance between the two is set according to the actual situation, preferably 3mm to 5mm.

[0051] In a preferred embodiment, a weight-reducing hole is provided at the bottom of the slider 4, which can reduce the weight of the slider 4 and thus reduce the overall weight of the device for ease of use. The groove on the slider 4 communicates with the weight-reducing hole to form a third through hole. The slider 4 is made of a conductive material, preferably a metal material, and more preferably an aluminum plate material with good conductivity and light weight.

[0052] In detail, in the preferred embodiment, at least four second receiving slots 1021 are provided on the side wall of the first receiving slot 102 opposite to the first through hole 101, for accommodating one metal piece 5 respectively. Specifically, four second receiving slots 1021 are provided, and one metal piece 5 is placed in each second receiving slot 1021, thus ensuring that the metal pieces 5 are insulated from each other. A power supply is connected between two metal pieces 5 to form at least two sets of circuits, one set of circuits also connected to an electric detonator, and the other set of circuits also connected to an alarm 7. It is understood that each metal piece 5 is connected to only one wire and connected to one power supply to form a circuit, and the two sets of circuits do not affect each other. The wires in each set of circuits are the same color and different color from the other set, making them easy to distinguish. In a specific implementation, the alarm 7 can be a buzzer.

[0053] Understandably, the upper cover 6 is shaped to correspond to the base 1. The electromagnetic pusher 2 is partially housed within the base 1, and the upper cover 6 secures the remaining upper portion of the electromagnetic pusher 2, protecting it. Similarly, the electromagnetic pusher 3 is typically a cylindrical object with a smaller-diameter, cylindrical output end connected to one end. Therefore, the upper cover 6 has a cylindrical through-hole (the second through-hole) corresponding to the electromagnetic pusher 3, allowing the electromagnetic pusher 3 to be placed vertically with its output end facing downwards. The base 1 has a first through-hole 101 to accommodate the electromagnetic pusher 2. The first through-hole 101 corresponds to the electromagnetic pusher 2, which is typically cylindrical with a slightly smaller-diameter output end. Therefore, the first through-hole 101 accommodating the electromagnetic pusher 2 consists of a larger cylindrical arc surface and a smaller cylindrical arc surface. The electromagnetic pusher 2 is placed horizontally and is at least partially housed within the first through-hole 101.

[0054] More specifically, in the preferred embodiment, the metal part 5 includes a connecting portion 501 and an inclined portion 502, with the inclined portion 502 and the connecting portion 501 connected at a certain angle. The metal part 5 is preferably formed by bending a copper material with a thickness of 0.5mm to 1.5mm that is integrally molded. The connecting portion 501 extends horizontally, and the inclined portion 502 extends into the first receiving groove 102. It is understood that the metal part 5 is made of a conductive material. When the slider 4 moves into position, it contacts the inclined portion 502 in the metal part 5, connecting the two metal parts 5 in the same circuit, equivalent to closing the switch of the circuit.

[0055] Among them, such as Figure 4 As shown, in the preferred embodiment, the angle A between the inclined portion 502 and the horizontal direction ranges from 20° to 45°, and is preferably 30°. The angle between the inclined portion 502 and the horizontal direction makes it easier for the slider 4 to contact the metal part 5 after sliding into position, and if the slider 4 squeezes and deforms the inclined portion 502, the metal part 5 has good elasticity and can also return to its original shape, which is convenient for repeated use.

[0056] Furthermore, in the preferred embodiment, the safety control device for detonation and explosion-proof testing also includes a connector. A connecting hole 5011 is provided on the connecting part 501, through which the connector connects the metal part 5 to the base 1. Specifically, the connector is a screw, and a threaded hole is provided on the second receiving groove 1021, allowing the metal part 5 to be fixed to the base 1 by the screw. Since there are multiple second receiving grooves 1021 arranged at equal intervals, and the multiple metal parts 5 connected to them are also arranged in parallel, the multiple metal parts 5 contact the slider 4 simultaneously.

[0057] Preferably, in the preferred embodiment, the metal part 5 further includes a fitting part 503, which is perpendicular to the connecting part 501. When the connecting part 501 is connected to the base 1, the fitting part 503 can fit against the side wall of the base 1, which can further ensure that the metal part 5 is well connected to the base 1, so that the metal part 5 is not easily displaced in the connected state.

[0058] The electromagnetic pin puller 3 relies on the energization of the coil to achieve the attraction movement of the armature and yoke, thereby driving the pull-back movement of the output pin of the electromagnetic pin puller 3. When the electromagnetic pin puller 3 is not energized, its output end is inserted into the side of the slider 4 near the second receiving groove 1021, locking the slider 4 and preventing it from moving arbitrarily. When the electromagnetic pin puller 3 is energized, its output end retracts, releasing the lock on the slider 4 and allowing the slider 4 to move.

[0059] More specifically, in the preferred embodiment, the upper cover 6 is also provided with a third receiving groove corresponding to the alarm 7 to receive the alarm 7. The base 1 and the upper cover 6 are made of non-conductive material.

[0060] Another aspect of the present invention provides a method for using a safety control device for detonation and explosion-proof testing. The specific operating steps of using the safety control device for detonation and explosion-proof testing as described above are as follows:

[0061] (1) After the safety control device for the detonation and explosion-proof test is installed, the output end of the electromagnetic pin puller 3 is inserted into the groove of the end of the slider 4 away from the electromagnetic pusher 2. Use a multimeter to check whether the circuit composed of the metal parts 5 is in an open circuit state. After ensuring that it is in an open circuit state, use the power supply to power the electromagnetic pin puller 3. Pull the electromagnetic pin puller 3 back to release the constraint on the slider 4.

[0062] (2) After supplying power to the electromagnetic pin puller 3 for 2s to 3s, the electromagnetic pusher 2 is then supplied with power for 2s to 3s. The electromagnetic pusher 2 pushes the slider 4 to move and makes the slider 4 contact the metal part 5.

[0063] (3) After the slider 4 moves into position, the electromagnetic pin puller 3 is de-energized. The output end of the electromagnetic pin puller 3 is inserted into another groove on the slider 4. The electromagnetic pin puller 3 locks the slider 4. After the electromagnetic pin puller 3 is de-energized for 2s to 3s, the electromagnetic pusher 2 is de-energized.

[0064] (4) Power the circuit connected to the alarm 7 and check whether the alarm 7 works. If the alarm 7 works, it can be determined that the metal part 5 is connected in place. Then stop the power supply to the circuit where the alarm 7 is located and evacuate the personnel. Power the circuit connected to the electric detonator and check whether the detonation or explosion-proof test of the fuse meets the requirements.

[0065] The safety control device and its usage method for detonation and explosion-proof testing in this invention have high overall safety. All operations can be performed remotely, and the alarm can be used to remotely check whether the slider has moved to the correct position to form a circuit between the metal parts. The device can be remotely controlled to switch the circuit from open to closed, and the operation method is time-sensitive; only by operating according to the correct sequence can the slider move to the correct position, achieving the switching of the position switch, thus ensuring high safety. This device ensures operational safety and prevents the detonation of electric detonators due to accidental power supply.

[0066] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A safety control device for detonation and explosion-proof testing, comprising a housing, characterized in that, It also includes a slider, an electromagnetic pusher, and an electromagnetic pin puller; the housing is provided with a first receiving groove corresponding to the slider to receive the slider and allow the slider to move within the first receiving groove; the first receiving groove is also connected to a first through hole and a second through hole; The output end of the electromagnetic pusher extends into the first receiving groove through the first through hole and connects to the slider; thus enabling the slider to slide within the first receiving groove under the action of the electromagnetic pusher. The slider is provided with multiple grooves corresponding to the output end of the electromagnetic pin puller, so that the output end of the electromagnetic pin puller extends into the first receiving groove through the second through hole and can be embedded in the groove. The first receiving groove has at least four second receiving grooves on the side wall opposite to the first through hole, for each of them to receive a metal part; The metal part includes a connecting part and an inclined part, the inclined part and the connecting part are connected at a certain angle, the connecting part extends in the horizontal direction, and the inclined part extends into the first receiving groove; A power source is connected between the two metal parts to form at least two sets of circuits, one set of circuits is also connected to an electric detonator, and the other set of circuits is also connected to an alarm; wherein, the slider is made of a conductive material, and the housing is made of a non-conductive material; After the slider moves to its position, power is first supplied to the circuit connected to the alarm. If the alarm is activated, power is stopped to the circuit where the alarm is located, and then power is supplied to the circuit connected to the electric detonator. The specific operating steps for using the safety control device for the detonation and explosion-proof tests are as follows: (1) After the safety control device for the detonation and explosion-proof test is installed, the output end of the electromagnetic pin puller is inserted into the groove at the end of the slider away from the electromagnetic pin puller. Use a multimeter to check whether the circuit composed of the metal parts is in an open circuit state. After ensuring that it is in an open circuit state, use a power supply to power the electromagnetic pin puller. The electromagnetic pin puller is pulled back to release the constraint on the slider. (2) After supplying power to the electromagnetic pin puller for 2s~3s, the electromagnetic pusher is then supplied with power for 2s~3s. The electromagnetic pusher pushes the slider to move and makes the slider contact the metal part. (3) After the slider moves to the position, the electromagnetic pin puller is de-energized, the output end of the electromagnetic pin puller is inserted into another groove on the slider, the electromagnetic pin puller locks the slider, and the electromagnetic pusher is de-energized 2s~3s after the electromagnetic pin puller is de-energized. (4) Power the circuit connected to the alarm and check whether the alarm works. If the alarm works, it can be determined that the metal part is connected in place. Then stop powering the alarm and evacuate the personnel. Power the circuit connected to the electric detonator and check whether the detonation or explosion-proof test of the fuse meets the requirements.

2. The safety control device for detonation and explosion-proof testing according to claim 1, characterized in that, The angle between the inclined portion and the horizontal direction ranges from 20° to 45°.

3. The safety control device for detonation and explosion-proof testing according to claim 1 or 2, characterized in that, It also includes a connector, on which a connection hole is provided, and the connector connects the metal part to the housing through the connection hole.

4. The safety control device for detonation and explosion-proof testing according to claim 1 or 2, characterized in that, The metal part also includes a fitting portion, which is perpendicular to the connecting portion and can fit against the side wall of the housing.

5. The safety control device for detonation and explosion-proof testing according to claim 1, characterized in that, The housing also has a third receiving slot corresponding to the alarm to receive the alarm.

6. The safety control device for detonation and explosion-proof testing according to claim 1 or 5, characterized in that, The output end of the electromagnetic pusher is threaded, and the slider is provided with a corresponding threaded hole, and the two are connected by threads.

7. The safety control device for detonation and explosion-proof testing according to claim 1, characterized in that, The bottom of the slider is provided with a weight reduction hole, and the groove on the slider communicates with the weight reduction hole to form a third through hole.

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