CN113334700B

CN113334700B - Plastic clothes hanger hot channel injection mold

Info

Publication number: CN113334700B
Application number: CN202110798279.2A
Authority: CN
Inventors: 吴晓锋; 董煌辉; 夏圆圆; 卢丽君; 万春莲
Original assignee: Quanzhou Min Qiao Plastic Co ltd
Current assignee: Quanzhou Min Qiao Plastic Co ltd
Priority date: 2021-07-15
Filing date: 2021-07-15
Publication date: 2023-03-03
Anticipated expiration: 2041-07-15
Also published as: CN113334700A

Abstract

The invention discloses a plastic clothes hanger hot channel injection mold which comprises a collecting box, wherein supporting legs are fixedly arranged on two sides of the bottom of the collecting box, a workbench is fixedly arranged on the top of the collecting box, a supporting block is fixedly arranged on one side of the top of the workbench, a static mold is fixedly arranged on the top of the workbench, and a hot channel box is fixedly arranged on the top of the supporting block. According to the plastic clothes hanger hot channel injection mold, the first motor, the feeding hopper, the heating rod, the extrusion screw, the material passing hole, the high-pressure injector, the injection hole, the static mold, the mold cavity, the movable mold, the second motor, the transmission mechanism, the mounting groove, the hot channel box and the limiting block are matched for use, and in the process of conveying materials in the hot channel box, the phenomenon that liquid is converted into solid due to self heat loss in the conveying process of the materials is avoided through heating of the heating rod, and the materials are always kept in the liquid state under the heating of the heating rod.

Description

Plastic clothes hanger hot channel injection mold

Technical Field

The invention relates to an injection mold, in particular to a plastic clothes hanger hot channel injection mold.

Background

The plastic clothes rack has two types of shapes, one is a flat and long rack body and a relatively narrow cross section of a rack shoulder, the slope of the rack inclination is small, and the plastic clothes rack is light, thin and suitable for airing light clothes. And the other type is a wider and shorter body frame just opposite to the former type. The two shoulder racks have larger inclination of inclination and thicker width, the shape is perfectly thick, and the plastic clothes rack is suitable for hanging heavy clothes, an injection mold is often used in the processing of the existing plastic clothes rack, the injection mold is a tool for producing plastic products and also a tool for endowing the plastic products with complete structure and accurate size, the injection mold is divided into two types of thermosetting plastic molds and thermoplastic plastic molds according to the forming characteristics, and the injection mold is divided into a transmission mold, a blow mold, a casting mold, a hot forming mold, a hot pressing mold, an injection mold and the like according to the forming process, wherein the hot pressing mold can be divided into three types of overflow type, semi-overflow type and non-overflow type in a flash mode, and the injection mold consists of a movable mold and a fixed mold.

However, in the conventional plastic clothes hanger hot-channel injection mold on the market, during the process of passing through the hot channel, the molten material gradually has liquid state to solid state along with the loss of heat of the material, and if the molten material is not injected into the mold cavity in the period, the injection port is likely to be blocked or the quality of the final product of the clothes hanger is likely to be influenced.

Disclosure of Invention

The invention aims to provide a hot channel injection mold for a plastic clothes rack, which aims to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides a plastics clothes hanger hot aisle injection mold, includes collecting box and riser, the equal fixed mounting in both sides of collecting box bottom has the supporting leg, the top fixed mounting of collecting box has the workstation, one side fixed mounting at workstation top has the supporting shoe, the top fixed mounting of workstation has quiet mould, the top fixed mounting of supporting shoe has the hot aisle case, the top fixed interlude of hot aisle case outer wall one side installs the feeder hopper, the other end fixed mounting of hot aisle case has first motor, the drive end fixed mounting of first motor has the extrusion screw, be provided with the heating rod between the inner wall of hot aisle case and the outer wall, the punishment in advance hole has been seted up to the one end of hot aisle case, the fixed interlude in one side of quiet mould installs high-pressure syringe, a plurality of injection hole has been seted up to the inside that is located high-pressure syringe one side, the movable hole has been seted up to the opposite side at workstation top, the front and the back of movable hole inner wall have all seted up the mounting groove, two the mounting groove is all rotated through the bearing of installation on its inner wall and is installed and is adjusted the die cavity, two be provided with drive mechanism between the adjustment screw rod, the fixed mounting of the movable mould is equipped with the stopper behind the movable mould.

As a further scheme of the invention: a plurality of slide opening has been seted up to one side of die cavity inner wall, slidable mounting has the ejector pin on the slide opening, the constant head tank has been seted up to the inner wall of slide opening, the inside fixed mounting of constant head tank has the gag lever post, the cover is equipped with the slider on the outer wall of gag lever post, the spring has been cup jointed to the one side that lies in the slider on the outer wall of gag lever post, the top of one side of riser and the equal fixed mounting in below have the fixed block, the riser passes through fixed block fixed mounting and has the clamp plate.

As a still further scheme of the invention: the improved roller conveying device is characterized in that a discharge hole is formed in one side of the top of the collecting box, a side hole is formed in the lower portion of one side of the collecting box, an electric roller and an auxiliary roller are arranged on the two sides of the bottom of the inner wall of the collecting box respectively, a conveying belt is arranged between the electric roller and the auxiliary roller, and transparent glass is fixedly embedded in the front of the collecting box.

As a still further scheme of the invention: two the equal fixed mounting in one side of mounting groove has the fixture block, the fixed orifices has been seted up to one side of fixture block.

As a still further scheme of the invention: and one side of the limiting block is provided with a threaded hole matched with the adjusting screw rod, and the limiting block is in threaded connection with the adjusting screw rod through the threaded hole formed in one side of the limiting block.

As a still further scheme of the invention: the transmission mechanism is composed of a driving wheel, a driven wheel and a belt, and the driving wheel and the driven wheel are in transmission connection through the belt.

As a still further scheme of the invention: one side of the sliding block is provided with a sliding hole matched with the limiting rod, and the sliding block is connected with the limiting rod in a sliding mode through the sliding hole formed in one side of the sliding block.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, through the matching use of the first motor, the feed hopper, the heating rod, the extrusion screw, the material passing hole, the high-pressure injector, the injection hole, the static mold, the mold cavity, the movable mold, the second motor, the transmission mechanism, the mounting groove, the hot channel box and the limiting block, the material is heated by the heating rod in the process of conveying the material in the hot channel box, the phenomenon that the material is converted from a liquid state into a solid state due to the loss of heat of the material in the conveying process is avoided, the material is kept in the liquid state all the time under the heating of the heating rod until leaving the interior of the hot channel box and is injected into the interior of the mold cavity, the phenomenon that the injection hole is blocked is avoided, the quality of a final product is also ensured, and meanwhile, through the spiral design of the heating rod, the contact surface with the hot channel box is wider, and the heating effect on the material is better.

2. According to the invention, through the matched use of the ejector rod, the vertical plate, the fixed block, the pressing plate, the sliding hole, the spring, the limiting rod, the sliding block and the positioning groove, under the elastic action of the spring, the ejector rod is driven by the sliding block to reset, the ejector rod does not need to be manually reset, the subsequent injection molding operation can be rapidly carried out, the production efficiency of the clothes hanger is improved, in the whole demolding process, manual demolding is not needed, through the mobility of the movable mold and the limiting of the mutual positions of the pressing plate and the ejector rod, the ejector rod can automatically eject the clothes hanger from the interior of the mold cavity in the process of separating the movable mold from the static mold, and subsequently, through the elastic action of the spring, in the process of closing the movable mold and the static mold, the ejector rod can automatically reset, so that the whole demolding process is automated, and the practicability is improved.

3. According to the invention, the side holes, the electric rollers, the conveying belt and the auxiliary rollers are matched for use, the conveying belt is driven to rotate through the matching of the conveying belt and the auxiliary rollers, the clothes hangers can be conveyed to the right side by the rotation of the conveying belt, and finally conveyed to the outside of the collecting box through the inside of the side holes, so that a worker can intensively collect the clothes hangers on one side of the collecting box, the injection molding, the forming, the demolding and the finished product conveying can be completed without excessive operators in the whole injection molding process, the phenomenon that the clothes hangers fall down once after the demolding is completed is avoided, the collection of the worker is carried out at a fixed point through the centralized collection of the collecting box and the centralized conveying of the conveying belt, the collection work of the worker is very easy, and the practicability is further improved.

Drawings

FIG. 1 is a schematic structural view of a hot runner injection mold for a plastic hanger;

FIG. 2 is a front view of a plastic hanger hot aisle injection mold;

FIG. 3 is a top view of a plastic hanger hot aisle injection mold;

FIG. 4 is a schematic side view of a movable mold of the hot runner injection mold for a plastic hanger;

FIG. 5 is a schematic view of a heater bar in a hot runner injection mold for a plastic hanger;

FIG. 6 is an enlarged schematic view of a hot runner injection mold for a plastic garment hanger at A in FIG. 1;

fig. 7 is an enlarged structural view of a hot channel injection mold for plastic clothes hangers, shown at B in fig. 1.

In the figure: the device comprises a collecting box 1, a side hole 2, a conveying belt 3, an electric roller 4, a supporting leg 5, a supporting block 6, a first motor 7, a feeding hopper 8, a heating rod 9, an extrusion screw rod 10, a material passing hole 11, a high-pressure injector 12, an injection hole 13, a static mold 14, a mold cavity 15, a movable mold 16, an ejector rod 17, a vertical plate 18, a fixed block 19, a pressing plate 20, a movable hole 21, an adjusting screw rod 22, a second motor 23, a mounting plate 24, a transmission mechanism 25, a discharging hole 26, a mounting groove 27, an auxiliary roller 28, transparent glass 29, a workbench 30, a hot channel box 31, a limiting block 32, a clamping block 33, a sliding hole 34, a spring 35, a limiting rod 36, a sliding block 37, a fixed hole 38 and a positioning groove 39.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

Referring to fig. 1 to 5, in the embodiment of the present invention, a plastic clothes hanger hot-channel injection mold comprises a collection box 1 and a vertical plate 18, wherein support legs 5 are fixedly mounted on both sides of the bottom of the collection box 1, a worktable 30 is fixedly mounted on the top of the collection box 1, a support block 6 is fixedly mounted on one side of the top of the worktable 30, a stationary mold 14 is fixedly mounted on the top of the worktable 30, a hot-channel box 31 is fixedly mounted on the top of the support block 6, one end of the hot-channel box 31 is fixedly connected with one side of the stationary mold 14, a feed hopper 8 is fixedly inserted and mounted above one side of the outer wall of the hot-channel box 31, a first motor 7 is fixedly mounted at the other end of the hot-channel box 31, a driving end of the first motor 7 penetrates through the other end of the hot-channel box 31 and extends into the hot-channel box 31, an extrusion screw 10 is fixedly mounted at a driving end of the first motor 7, a heating rod 9 is disposed between the inner wall and outer wall of the hot-channel box 31, the heating rod 9 is spirally shaped, one end of the hot-channel box 31 is provided with a material passing hole 11, one side of the stationary mold 14 is fixedly mounted, a high-pressure injector 12 is disposed on one side of the high-pressure injector 12, two movable injection holes are disposed on one side of the inner side of the stationary mold 14, a movable screw rod 13 disposed on the movable mounting groove, a movable mounting plate 21, a movable screw rod mechanism, a movable screw 27 is disposed on the movable mounting plate 21, and a rear surface of the movable screw 21, a movable screw 27 disposed on the movable mounting plate 30, and a movable mounting plate 30, a rear surface of the movable screw rod mounting plate 21, a screw 21, a rear surface of the movable screw 21, and a rear surface of the movable mounting plate 30, a screw 27 is disposed on the movable mounting plate 30, and a rear surface of the movable mounting plate 30, a screw 21, a screw rod mounting groove 21, a screw rod mounting plate 21 is disposed on the movable mounting plate 21, and a rear surface of the movable mounting plate 30, a rear surface of the movable mounting mechanism, and a screw 21, and the drive end of second motor 23 and the one end fixed connection of an accommodate the lead screw 22, all the cover is equipped with stopper 32 on two accommodate the lead screw 22's the outer wall, and stopper 32 and corresponding mounting groove 27 sliding connection, fixed mounting has movable mould 16 between the opposite side of two stopper 32, form a plurality of die cavity 15 after quiet mould 14 and the laminating of movable mould 16, the material is at the inside in-process of carrying of hot runner case 31, through the heating of heating rod 9 to the material, the in-process of having avoided the material at the transport, because of self thermal losing, turn into solid-state phenomenon by liquid.

Referring to fig. 1, fig. 3, fig. 4 and fig. 6, in the application, a plurality of slide hole 34 has been seted up to one side of die cavity 15 inner wall, slidable mounting has ejector pin 17 on slide hole 34, and the one end of ejector pin 17 flushes the other end with the inner wall of die cavity 15 and extends the opposite side of movable mould 16, constant head tank 39 has been seted up to the inner wall of slide hole 34, the inside fixed mounting of constant head tank 39 has gag lever post 36, the cover is equipped with slider 37 on the outer wall of gag lever post 36, and slider 37 and ejector pin 17 fixed connection, it has spring 35 to lie in one side of slider 37 cup joint on the outer wall of gag lever post 36, the top and the equal fixed mounting in below of one side of riser 18 have fixed block 19, riser 18 has clamp plate 20 through fixed block 19 fixed mounting, need not artifical manual drawing of patterns, through the mobility of movable mould, and the spacing of clamp plate and ejector pin position each other, make the movable mould break away from the in-process of static mould, the ejector pin can be automatic with the clothes hanger from the inside of die cavity voluntarily, follow-up through the elastic action of spring, in the closed in-process of movable mould, the ejector pin is automatic again, make whole drawing of the whole drawing of a mould, practicality improve.

Referring to fig. 1, in this application, discharge opening 26 has been seted up to one side at collecting box 1 top, and discharge opening 26 is located the activity hole 21 under, side opening 2 has been seted up to the below of collecting box 1 one side, the both sides of collecting box 1 inner wall bottom are provided with electronic roller 4 and supplementary roller 28 respectively, be provided with conveyer belt 3 between electronic roller 4 and the supplementary roller 28, the fixed embedding in front of collecting box 1 installs transparent glass 29, be convenient for concentrate the collection to clothes hanger, can observe the transport condition of the inside clothes hanger of collecting box 1 at any time through transparent glass 29, if discover abnormal conditions, so that the staff makes emergency treatment.

Referring to fig. 1, fig. 3 and fig. 7, in this application, the equal fixed mounting in one side of two mounting grooves 27 has fixture block 33, fixed orifices 38 have been seted up to one side of fixture block 33, and accommodate the lead screw 22 runs through fixture block 33 through fixed orifices 38, the diameter of fixed orifices 38 is greater than accommodate the lead screw 22's diameter, it is spacing to the position of movable mould 16, avoid stopper 32 to the distance that the left side removed too big, lead to taking place to contradict between movable mould 16 and the clamp plate 20, through the restriction of fixture block 33 to stopper 32 position, guarantee that the clothes hanger can normally demold the mould alright.

Referring to fig. 3, in the present application, a threaded hole adapted to the adjusting screw 22 is formed at one side of the limiting block 32, and the limiting block 32 is in threaded connection with the adjusting screw 22 through the threaded hole formed at one side thereof, so that the effect of the lateral movement of the movable mold 16 is achieved in a threaded transmission manner.

Referring to fig. 1 and 3, in this application, drive mechanism 25 comprises the action wheel, follows driving wheel and belt, and the action wheel with follow the driving wheel and pass through belt transmission and connect, through drive mechanism 25's transmission, make two accommodate the lead screw 22 rotate simultaneously, take place screw drive with stopper 32 simultaneously, make two stoppers 32 carry out horizontal removal in step to guarantee the steady removal of movable mould 16.

Referring to fig. 6, in the present application, a sliding hole adapted to the limiting rod 36 is formed at one side of the sliding block 37, and the sliding block 37 is slidably connected to the limiting rod 36 through the sliding hole formed at one side thereof.

The working principle of the invention is as follows:

referring to fig. 1, 2, 3, 4 and 5, when in use, electrical components appearing in the present application are all externally connected to a power supply and a control switch, when injection molding of the clothes hanger is required, the second motor 23 is controlled by the switch to start working, the "second motor 23 is a forward and reverse motor, and the model of the second motor 23 is ZGA37RG", the driving end of the second motor 23 drives one adjusting screw 22 to rotate, the two adjusting screws 22 rotate simultaneously through the transmission relationship of the transmission mechanism 25, the material enters the interior of the hot channel box 31 through the feed hopper 8 through the thread transmission relationship between the stopper 32 and the adjusting screw 22 and the sliding relationship between the stopper 32 and the mounting groove 27 through the transmission relationship between the stopper 32 and the movable die 16, so that the movable die 16 and the stationary die 14 are closed to form the die cavity 15, the melted material is added into the feed hopper 8, the material enters the interior of the hot channel box 31 through the feed hopper 8, the first motor 7 and the heating rod 9 are controlled by the switch to start working, the driving end of the extrusion screw 10 rotates, the high-pressure injection screw 10 rotates, the high pressure injection material is easily injected into the hot channel 12, and the hot channel box 11, the high pressure injection material is easily heated by the high pressure injection injector 12, and the high pressure injection channel 12, penetrate into the inside of die cavity 15, after the cooling solidification, obtain the shaping clothes hanger, the material is at the in-process of the inside transport of hot channel case 31, through the heating of heating rod 9 to the material, the material is at the in-process of carrying, because of the loss of self heat, turn into solid-state phenomenon by liquid, under the heating of heating rod 9, the material keeps the liquid state always, until leaving the inside of hot channel case 31, penetrate into the inside of die cavity 15, avoid causing the phenomenon of jam to injection hole 13, the quality of final product has also been ensured, simultaneously through the spiral helicine design of heating rod 9, make the contact surface with hot channel case 31 wider, it is better to the heating effect of material.

Referring to fig. 1, 2, 4 and 6, in use, after the clothes hanger is molded, the clothes hanger needs to be demolded, at this time, the movable mold 16 is moved to the left side through the driving control of the second motor 23, in the moving process, the ejector rod 17 contacts the press plate 20, after the ejector rod 17 contacts the press plate 20, the movable mold 16 still moves to the left side by a proper distance, and simultaneously drives the ejector rod 17 to move to the inside of the mold cavity 15, in the sliding process of the ejector rod 17 on the sliding hole 34, the slider 37 is driven to slide on the outer wall of the limit rod 36, in the sliding process, the slider 37 extrudes the spring 35, and simultaneously, the ejector rod 17 moves to the inside of the mold cavity 15, the molded clothes hanger in the mold cavity 15 is ejected and directly falls off, and then falls into the collecting box 1 through the movable hole 21 and the discharging hole 26, so as to complete the demolding operation of the clothes hanger, then the movable mold 16 and the static mold 14 can be closed, the ejector rod 17 can be gradually separated from the contact with the pressing plate 20 in the process that the movable mold 16 and the static mold 14 are closed, so that the pressing plate 20 loses the limiting effect on the ejector rod 17, the ejector rod 17 is driven by the slide block 37 to reset under the elastic action of the spring 35, the ejector rod 17 does not need to be manually reset, the subsequent injection molding operation can be rapidly carried out, the production efficiency of the clothes hanger is improved, the clothes hanger can be automatically ejected out from the inside of the mold cavity 15 by the ejector rod 17 in the whole demolding process without manually demolding, through the mobility of the movable mold 16 and the limiting of the mutual positions of the pressing plate 20 and the ejector rod 17, the ejector rod 17 can automatically reset in the process that the movable mold 16 and the static mold 14 are closed, and the whole demolding process is automated, the practicability is improved.

Referring to fig. 1, during the use, the drawing of patterns is accomplished the back, clothes hanger falls into the inside of collecting box 1, finally can directly drop at the top of conveyer belt 3, this moment through the electronic roller 4 of on-off control start work, cooperation through conveyer belt 3 and auxiliary roller 28, it rotates to drive conveyer belt 3, the rotation of conveyer belt 3 can be carried clothes hanger to the right side, finally pass through the inside of side opening 2, carry to the outside of collecting box 1, the staff concentrates the collection alright to clothes hanger in one side of collecting box 1, unusual facility, whole in-process of moulding plastics, need not too much operating personnel, alright accomplish whole injection molding, the shaping, the process that drawing of patterns and finished product were carried, avoided drawing of patterns clothes hanger to accomplish the back, drop one place, concentrate through collecting of collecting box 1 and the concentrated transport of conveyer belt 3, carry out the fixed point and collect, make staff's collection work, become very light, its practicality has further been improved.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and/or modifications of the invention can be made, and equivalents and modifications of some features of the invention can be made without departing from the spirit and scope of the invention.

Claims

1. The utility model provides a plastics clothes hanger hot aisle injection mold, includes collecting box (1) and riser (18), its characterized in that: the supporting legs (5) are fixedly mounted on two sides of the bottom of the collecting box (1), a workbench (30) is fixedly mounted on the top of the collecting box (1), a supporting block (6) is fixedly mounted on one side of the top of the workbench (30), a static die (14) is fixedly mounted on the top of the workbench (30), a hot channel box (31) is fixedly mounted on the top of the supporting block (6), a feeding hopper (8) is fixedly and alternately mounted above one side of the outer wall of the hot channel box (31), a first motor (7) is fixedly mounted at the other end of the hot channel box (31), an extrusion screw (10) is fixedly mounted at the driving end of the first motor (7), a heating rod (9) is arranged between the inner wall and the outer wall of the hot channel box (31), a material passing hole (11) is formed in one end of the hot channel box (31), a high-pressure injector (12) is fixedly and alternately mounted on one side of the static die (14), a plurality of high-pressure injectors (13) are formed in one side of the inner part of the high-pressure injector (12), a plurality of installing holes (21) are formed in the other side of the top of the workbench (30), two installing grooves (27) are formed in the front side of the installing groove, and two installing grooves (27) are respectively formed in the adjusting screw rod (27), two be provided with drive mechanism (25) between accommodate the lead screw (22), one side fixed mounting of workstation (30) has mounting panel (24), the bottom fixed mounting of mounting panel (24) has second motor (23), two all the cover is equipped with stopper (32) on the outer wall of accommodate the lead screw (22), two fixed mounting has movable mould (16) between the opposite side of stopper (32), form a plurality of die cavity (15) after quiet mould (14) and movable mould (16) laminate.

2. The plastic hanger hot runner injection mold of claim 1, wherein: a plurality of slide opening (34) have been seted up to one side of die cavity (15) inner wall, slidable mounting has ejector pin (17) on slide opening (34), constant head tank (39) have been seted up to the inner wall of slide opening (34), the inside fixed mounting of constant head tank (39) has gag lever post (36), the cover is equipped with slider (37) on the outer wall of gag lever post (36), spring (35) have been cup jointed to one side that lies in slider (37) on the outer wall of gag lever post (36), the top and the equal fixed mounting in below of one side of riser (18) have fixed block (19), riser (18) have clamp plate (20) through fixed block (19) fixed mounting.

3. The plastic hanger hot runner injection mold of claim 1, wherein: discharge opening (26) have been seted up to one side at collecting box (1) top, side opening (2) have been seted up to the below of collecting box (1) one side, the both sides of collecting box (1) inner wall bottom are provided with electronic roller (4) and supplementary roller (28) respectively, be provided with conveyer belt (3) between electronic roller (4) and supplementary roller (28), the front fixed mosaic of collecting box (1) installs transparent glass (29).

4. The plastic hanger hot runner injection mold of claim 1, wherein: two inside one side of mounting groove (27) all fixed mounting have fixture block (33), fixed orifices (38) have been seted up to one side of fixture block (33).

5. The plastic hanger hot runner injection mold of claim 1, wherein: one side of the limiting block (32) is provided with a threaded hole matched with the adjusting screw rod (22), and the limiting block (32) is in threaded connection with the adjusting screw rod (22) through the threaded hole formed in one side of the limiting block.

6. The plastic hanger hot runner injection mold of claim 1, wherein: the transmission mechanism (25) consists of a driving wheel, a driven wheel and a belt, and the driving wheel and the driven wheel are in transmission connection through the belt.

7. A plastic hanger hot runner injection mold as claimed in claim 2, wherein: one side of the sliding block (37) is provided with a sliding hole matched with the limiting rod (36), and the sliding block (37) is connected with the limiting rod (36) in a sliding mode through the sliding hole formed in one side of the sliding block.