Constant pressure device of nailing gun

Abstract

The utility model discloses a constant-pressure device of a nailing gun, relates to the technical field of electric tools, and mainly solves the problem of how to ensure the normal use of the nailing gun. A constant pressure device of a nailing gun comprises a cylinder body, a piston and a cylinder cover, the cylinder cover, the piston and the cylinder body are matched to form a sealed cavity, a comprehensive valve is arranged on the cylinder cover and comprises a valve body and a hollow valve element used for inflation, valve holes are formed in the two ends of the valve body and used for allowing the hollow valve element to move in a reciprocating mode, and a blocking part is arranged on the hollow valve element. The blocking part is connected with the inner side wall of the valve body through a reset piece, when the pressure in the cavity is higher than a threshold value and affected by the internal pressure, the blocking part drives the reset piece to elastically deform, the cavity is made to communicate with the outside through the valve holes, and the reset piece drives the blocking part to abut against the side wall of one valve hole to form sealing till the internal pressure is reduced to the threshold value. And the exhaust valve is integrated on the hollow valve element, so that the internal pressure is constant, and the use safety is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of power tools, in particular to a nail gun, and more particularly to a constant pressure device for a nail gun. Background Art

[0002] The following discussion of the background of the utility model is intended to facilitate the understanding of the utility model. However, it should be understood that the discussion does not recognize or admit that any aspect of the discussion is part of the common general knowledge before the filing date of this application.

[0003] As a tool for driving nails or other metal solids into wooden boards, steel bars or other base materials, nail guns are widely used in industries such as furniture manufacturing, construction, and transportation. Nail guns can be divided into pneumatic nail guns, electric nail guns, and manual nail guns according to different driving methods. They include a firing pin assembly, a nozzle, and a magazine. The nails are mainly pushed upward by a compression spring in the magazine and then quickly moved through the firing pin assembly after entering the nozzle, and then the nails enter the object to be nailed through the nozzle.

[0004] In the case of an electric nail gun, it usually uses a motor to drive a piston in a cylinder to move, thereby compressing the gas in the cylinder, and then providing power for the firing pin to move forward quickly and drive out the nail. Among them, to ensure the stability of the firing pin driving the nail, it is usually necessary to ensure the airtightness of the cylinder to avoid power attenuation caused by internal gas leakage.

[0005] For example, a sealing structure of an electric tool in the prior art mainly drives a second piston by a motor. Among them, since the first working chamber and the second working chamber are connected and sealed through a cylinder head, the total volume of the first working chamber and the second working chamber decreases, and the internal air pressure increases until the motor drives the engaging member to disengage from the limiting portion on the firing pin, and the first piston pushes the firing pin to drive out the nail under the action of the internal pressure. Since a certain air pressure is required inside to provide sufficient thrust for the firing pin, it is usually manually inflated after assembly. However, due to many influencing factors of air pressure change, the accuracy during the inflation process cannot be guaranteed, and the nail gun cannot be used normally due to too high internal pressure during use. Summary of the Utility Model

[0006] The purpose of the utility model is to propose a constant pressure device for a nail gun in view of the above problems existing in the prior art. The technical problem to be solved by the utility model is: how to ensure the normal use of the nail gun.

[0007] The purpose of the present utility model can be achieved by the following technical solutions: A constant pressure device for a nail gun, comprising a cylinder block, a piston, and a cylinder head. The cylinder head, piston, and cylinder block cooperate to form a sealed chamber. A combined valve is provided on the cylinder head. It is characterized in that the combined valve includes a valve body and a hollow valve core for inflating. Both ends of the valve body are provided with valve holes for the hollow valve core to reciprocate. A blocking portion is provided on the hollow valve core, and the blocking portion is connected to the inner side wall of the valve body through a reset member. When the pressure in the chamber is higher than the threshold value, affected by the internal pressure, the blocking portion drives the reset member to undergo elastic deformation, and the chamber is connected to the outside through the valve hole until the internal pressure drops to the threshold value, and the reset member drives the blocking portion to abut against the side wall of one of the valve holes to form a seal.

[0008] The basic principle of this application is the same as that of the existing electric nail gun. A sealed chamber is formed by the cooperation of the cylinder head, one side of the piston, and the cylinder block. By compressing the volume of the chamber, a forward thrust is provided for the piston. Compared with the prior art, in this application, a combined valve is provided on the original cylinder head, and the chamber is connected to the outside through the valve holes at both ends of the combined valve, facilitating the entry of high-pressure air into the chamber for inflation. A hollow valve core is provided in the combined valve, and a reset member is provided between the blocking portion on the hollow valve core and the valve body, and the blocking portion can cooperate with the pore wall of the valve hole to form a seal, reducing the influence of the change in internal air pressure during the reciprocating movement of the piston on the hollow valve core, ensuring its normal use. And when the internal pressure is higher than the threshold value, affected by the gas law, a thrust that can overcome the elastic force of the reset member is generated, and then the blocking portion is pushed in the opposite direction of nail driving, so that the chamber can exhaust air to the outside through the valve hole until the internal pressure decreases and its thrust cannot overcome the elastic force of the reset member, and the reset member drives the blocking portion to move to complete the seal. By the change in internal pressure during the inflation process, the hollow valve core is pushed to move, thereby ensuring the constancy of the internal pressure and avoiding the abnormal use of the nail gun due to excessive internal pressure. Among them, the threshold value refers to the air pressure value that can generate a thrust equal to the elastic force of the reset member, that is, the air pressure value in the chamber when the firing pin is locked under normal use conditions.

[0009] In the above constant pressure device for a nail gun, the valve body includes a valve cover and a valve seat. The valve seat and the valve cover cooperate to form an inner cavity. The valve holes are respectively located on the valve seat and the valve cover. The chamber is connected to the outside through the inner cavity. Dividing the valve body into a valve cover and a valve seat facilitates the installation of the hollow valve core, and when the internal pressure is too high, the excess gas in the chamber can be discharged through the inner cavity to keep the internal air pressure constant.

[0010] In the constant pressure device of the above nail gun, the blocking part is located at one end of the hollow valve core. An air inlet valve shaft is provided at the other end of the hollow valve core. The air inlet valve shaft is located inside the hollow valve core. The air inlet valve shaft reciprocates to block or allow high-pressure gas to enter the chamber through the hollow valve core. By providing an air inlet valve shaft on the hollow valve core, during the inflation process with an external air pump, if the internal pressure is greater than the threshold value, the hollow valve core will drive the joint on the air pump to move backward, indicating to the staff that the internal pressure has reached the threshold value while exhausting air.

[0011] In the constant pressure device of the above nail gun, there is a certain distance between the circumferential side of the blocking part and the inner wall of the inner cavity. By setting a distance between the blocking part and the circumferential side of the inner cavity, while ensuring sealing, it is convenient for the gas in the inner cavity to flow and for exhausting air.

[0012] In the constant pressure device of the above nail gun, the end of the hollow valve core with the air inlet valve shaft is in clearance fit with the valve hole. By making the valve hole in clearance fit with the hollow valve core, it is convenient for exhausting air and reducing the internal air pressure.

[0013] In the constant pressure device of the above nail gun, the resetting member is located in the inner cavity. One end of the resetting member abuts against the valve cover, and the other end abuts against the blocking part. The hollow valve core reciprocates along the axis of the cylinder block, causing the resetting member to undergo elastic deformation. Since the hollow valve core reciprocates on the axis of the cylinder block, it avoids uneven force caused by the offset of the hollow valve core and enables the normal discharge of the internal gas.

[0014] In the constant pressure device of the above nail gun, the resetting member is sleeved on the hollow valve core. One end of the valve seat is provided with internal threads and external threads, and the axes of the internal threads and the external threads coincide with the axis of the hollow valve core.

[0015] In the constant pressure device of the above nail gun, the internal threads and the external threads have the same or opposite helix directions.

[0016] In the constant pressure device of the above nail gun, one side of the external threads can abut against the valve cover, and the other side is provided with a thread groove. A sealing ring is sleeved on the thread groove, and a groove for accommodating the sealing ring is provided on the cylinder head cover.

[0017] In the constant pressure device of the above nail gun, a firing pin is provided on the piston, and a lifting part is provided on the nail gun. The lifting part drives the piston to move through the firing pin until the pressure in the chamber reaches the threshold value.

[0018] Compared with the prior art, the present utility model has the following advantages:

[0019] 1. In this application, a combined valve is provided on the cylinder head, and an intake valve shaft with a one-way valve function is arranged inside the hollow valve core. While enabling the staff to inflate the chamber through the hollow valve core, when the internal pressure is too high, the blocking part on the hollow valve core can also be pushed to connect the chamber with the outside through the valve body and discharge some of the internal gas until the internal pressure drops to a certain value, at which time the reset part pushes the blocking part to fit and seal with the valve hole. Thus, while ensuring the constancy of the internal air pressure, it avoids the nail gun being unable to be used normally due to excessive internal air pressure before leaving the factory, integrates the inflation and exhaust functions, simplifies the product structure, and enables the operator to know the internal pressure situation only through the movement change of the hollow valve core.

[0020] 2. By adopting two threads with opposite rotation directions, the influence of the reciprocating movement of the hollow valve core on the airtightness of the combined valve is reduced.

[0021] 3. The intake valve shaft is arranged inside the hollow valve core to combine intake and exhaust into one, avoiding the reduction of the strength of the cylinder head due to multiple openings, and using a clamping method to fix the valve body on the cylinder head, improving the stability of the fixation. Description of the Drawings

[0022] Figure 1 is the schematic exploded view of the nail gun in the present utility model;

[0023] Figure 2 is the schematic bottom-up sectional view of the nail gun in the present utility model;

[0024] Figure 3 is the schematic exploded view of the combined valve in the present utility model;

[0025] Figure 4 is Figure 2 the partial enlarged view in the normal state

[0026] Figure 5 is Figure 2 the partial enlarged view in the state of excessive internal air pressure;

[0027] In the figure: 1. Nail gun body; 1a. Firing pin; 1a1. Card slot; 1b. Driver; 1b1. Lifter; 1c. Nozzle; 1c1. Magazine; 1d. Locking mechanism; 2. Cylinder block; 2a. Cylinder head; 2a1. Groove; 2b. Piston; 2c. Chamber; 3. Combined valve; 3a. Valve body; 3a1. Valve seat; 3a2. Valve cover; 3b. Valve hole; 3c. Inner cavity; 4. Hollow valve core; 4a. Blocking part; 4a1. Sealing member; 4a2. Contact surface; 4b. Intake valve shaft; 5. Reset part; 6. Sealing ring; Detailed Description of the Preferred Embodiment

[0028] The following are specific embodiments of the present utility model and, in conjunction with the accompanying drawings, further describe the technical solutions of the present utility model. However, the present utility model is not limited to these embodiments.

[0029] Embodiment 1

[0030] As Figure 1 and Figure 2 shown, the present application includes a nail driving body 1 composed of a firing pin 1a, a driving machine 1b, a nozzle 1c, and a nail magazine 1c1. A lifter 1b1 is provided on the driving machine 1b. The lifter 1b1 is snap-connected to a plurality of card slots 1a1 on the firing pin 1a. The other end of the firing pin 1a is located in a cylinder block 2. A piston 2b fixedly connected to the firing pin 1a is provided in the cylinder block 2. One end of the cylinder block 2 is connected to the nail driving body 1, and the other end is covered with a cylinder head 2a. The cylinder head 2a and the piston 2b cooperate to form a sealed chamber 2c. A comprehensive valve 3 is provided on the cylinder head 2a. The comprehensive valve 3 is located at the center of the cylinder head 2a and coincides with the central axis of the piston 2b. Among them, the nail magazine 1c1 is used to store nails and send the nails located inside into the nozzle 1c. The firing pin 1a is snap-connected through a locking mechanism. Among them, regarding the specific structures of the lifter 1b1 and the piston 2b, they are prior art known to those skilled in the art before this application and will not be elaborated here.

[0031] As Figure 3 shown, the comprehensive valve 3 of the present application can be divided into a valve seat 3a1, a sealing ring 6, a hollow valve core 4, a reset member 5, and a valve cover 3a2 along the length direction. Among them, the cylinder head 2a is located between the valve cover 3a2 and the valve seat 3a1. A valve hole 3b is opened on the valve seat 3a1, and an external thread is provided at one end of the valve seat 3a1. An internal thread capable of meshing with the external thread on the valve seat 3a1 is provided on the cylinder head 2a. A groove 2a1 is provided on one side of the cylinder head 2a. The groove 2a1 is disposed opposite to the valve seat 3a1, and a sealing ring 6 is provided between the side wall of the groove and the side wall of the valve seat 3a1. An external thread threadedly connected to the valve cover 3a2 is provided at one end of the valve cover 3a2, and a blocking portion 4a is provided at one end of the hollow valve core 4, and a reset member 5 is sleeved at the other end.

[0032] As Figure 4 and Figure 5As shown, the external thread on the valve cover 3a2 mates with the internal thread of the valve seat 3a1, and the external thread of the valve seat 3a1 mates with the internal thread of the cylinder head 2a. The valve cover 3a2 and the valve seat 3a1 are threadedly connected to clamp the cylinder head 2a therebetween, and cooperate to form a valve body 3a. An inner cavity is formed by the cooperation of the valve cover 3a2 and the valve seat 3a1. Valve holes 3b are provided at both ends of the valve body 3a. The chamber 2c communicates with the inner cavity through the valve hole 3b located on the valve cover 3a2, and the inner cavity communicates with the outside through the valve hole 3b located on the valve cover 3a2. The hollow valve core 4 is disposed between the two valve holes 3b. An intake valve shaft 4b is provided at one end of the hollow valve core 4 and passes through the valve hole 3b located on the valve cover 3a2. A blocking portion 4a is circumferentially provided at the other end. The blocking portion 4a can be in close contact with the side wall on the valve seat 3a1 to form a seal. Among them, a reset member 5 is provided in the inner cavity. The reset member 5 is sleeved outside the hollow valve core 4, and one end abuts against the inner side wall of the valve cover 3a2, and the other end abuts against one side wall of the blocking portion 4a. The above side wall is the side that does not contact the side wall of the valve hole 3b. Among them, the diameter of the blocking portion 4a is larger than the diameter of the valve hole 3b, and there is also a certain distance between the two side walls of the valve seat 3a1. The blocking portion 4a includes a top surface 4a2 that abuts against the reset member 5 and a seal member 4a1 embedded on the hollow valve core 4. The seal member 4a1 abuts against the side wall of the valve hole 3b to form a seal. The hollow valve core 4 and the valve hole 3b on the valve cover 3a2 also adopt a clearance fit. In the normal state, the reset member 5 that has completed pre-compression pushes the seal member 4a1 on the hollow valve core 4 to closely fit with the inner side wall of the valve hole 3b. When the thrust generated by the internal air pressure is greater than the elastic force of the reset member 5, the blocking portion 4a is pushed backward to separate the seal member 4a1 from the side wall of the valve hole 3b, and the chamber 2c communicates with the outside through the inner cavity of the combined valve 3. In this embodiment, the reset member 5 is a spring, but other reset members 5 that can make the blocking portion 4a fit with the side wall of the valve hole 3b and elastically deform under the influence of the internal pressure are not excluded.

[0033] In summary, the basic working principle of the present application is that the drive motor 1b drives the striker 1a to move backward through the lifter 1b1, and then pushes the piston 2b to move backward, so that the volume of the chamber 2c continuously decreases. According to Boyle's law, that is, the volume is inversely proportional to the pressure. Accordingly, the pressure in the chamber 2c gradually rises as the piston 2b moves backward until the piston 2b moves to the corresponding position and the lifter 1b1 stops rotating, and the stapler completes the preparation work before stapling. Among them, after the assembly is completed, it is usually necessary to inflate manually to ensure that there is enough thrust inside, but manual inflation usually cannot accurately control the internal air pressure.

[0034] Accordingly, based on this application, the inflation valve and the exhaust valve are integrated on the same hollow valve core 4. When the internal volume of the cylinder block 2 remains unchanged, the staff continuously inflates it to increase the internal pressure. At this time, since the firing pin 1a is clamped and connected to the locking mechanism 1d, the piston 2b cannot move. At this time, if the internal pressure is too high, the blocking portion 4a will be affected by the internal thrust. After overcoming the elastic force of the reset member 5, the seal 4a1 separates from the side wall of the valve hole 3b under the action of the thrust. Since the diameter of the blocking portion 4a is smaller than the inner diameter of the valve seat 3a1, and there is a clearance fit between the hollow valve core 4 and the valve hole 3b on the valve cover 3a2, after the seal 4a1 separates from the side wall of the valve hole 3b, the internal gas is discharged through the valve holes 3b on both side walls of the inner cavity. At the same time, the inflation device connected to the hollow valve core 4 will move upward at this time as the hollow valve core 4 moves, prompting the operator that the internal pressure has reached the threshold. After stopping inflation, the hollow valve core 4 moves downward under the thrust of the reset member 5 to perform sealing, avoiding pressure reduction caused by internal gas leakage and ensuring that the internal pressure is stably maintained at a constant pressure effect.

[0035] And during the process of nail driving, the lifter 1b1 drives the piston 2b to move backward, further compressing the volume in the chamber 2c and increasing the thrust. At this time, the part of the pressure higher than the threshold will be reduced due to the gas in the chamber 2c being discharged through the integrated valve 3, thereby ensuring the constancy of the internal pressure and avoiding the impact on the normal operation of the nail gun caused by excessive pressure. By adopting the method of decompression twice, it can be made ready for use without further inflation while reducing the impact of surrounding changes on the air pressure.

[0036] The specific embodiments described herein are merely illustrative of the spirit of the present utility model. Those skilled in the art of the present utility model can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, but will not deviate from the spirit of the present utility model or exceed the scope defined by the appended claims.

[0037] Although terms such as 1, nail driving body; 1a, firing pin; 1a1, card slot; 1b, driving machine; 1b1, lifter; 1c, nozzle; 1c1, nail magazine; 1d, locking mechanism; 2, cylinder block; 2a, cylinder head; 2a1, groove; 2b, piston; 2c, chamber; 3, integrated valve; 3a, valve body; 3a1, valve seat; 3a2, valve cover; 3b, valve hole; 3c, inner cavity; 4, hollow valve core; 4a, blocking portion; 4a1, seal; 4a2, abutting surface; 4b, intake valve shaft; 5, reset member; 6, sealing ring are used more in this article for the convenience of describing and explaining the essence of the present utility model; interpreting them as any additional limitation is contrary to the spirit of the present utility model.

Claims

1. A constant pressure device for a nail gun, comprising a cylinder body (2), a piston (2b) and a cylinder head (2a), wherein the cylinder head (2a), the piston (2b) and the cylinder body (2) cooperate to form a sealed chamber (2c), wherein the cylinder head (2a) is provided with an integrated valve (3), wherein the integrated valve (3) comprises a valve body (3a) and a hollow valve core (4) for inflating, wherein: Both ends of the valve body (3a) are provided with valve holes (3b), and the valve holes (3b) are used for the reciprocating movement of the hollow valve core (4). The hollow valve core (4) is provided with a blocking portion (4a), and the blocking portion (4a) is connected to the inner wall of the valve body (3a) through a reset member (5). When the pressure in the chamber (2c) is higher than a threshold value, the blocking portion (4a) is affected by the internal pressure and drives the reset member (5) to undergo elastic deformation, and enables the chamber (2c) to communicate with the outside through the valve hole (3b), until the internal pressure drops to the threshold value, and the reset member (5) drives the blocking portion (4a) to abut against one of the side walls of the valve hole (3b) to form a seal.

2. The constant pressure device of the nail gun according to claim 1, characterized in that: The valve body (3a) comprises a valve cover (3a2) and a valve seat (3a1), wherein the valve seat (3a1) cooperates with the valve cover (3a2) to form an inner cavity (3c), the valve hole (3b) is respectively located on the valve seat (3a1) and the valve cover (3a2), and the chamber (2c) is connected to the outside through the inner cavity (3c).

3. The constant pressure device of the nail gun according to claim 2, characterized in that: The blocking portion (4a) is located at one end of the hollow valve core (4), and the other end of the hollow valve core (4) is provided with an intake valve shaft (4b), and the intake valve shaft (4b) is located inside the hollow valve core (4). The intake valve shaft (4b) moves back and forth and is used to block or allow high-pressure gas to enter the chamber (2c) through the hollow valve core (4).

4. The constant pressure device of the nail gun according to claim 3, characterized in that: There is a certain distance between the peripheral side of the blocking portion (4a) and the inner wall of the inner cavity (3c).

5. The constant pressure device of the nail gun according to claim 3, characterized in that: One end of the air intake valve shaft (4b) on the hollow valve core (4) is clearance-matched with the valve hole (3b).

6. The constant pressure device of a nail gun according to any one of claims 2 to 5, characterized in that: The reset member (5) is located in the inner cavity (3c), and one end of the reset member (5) abuts against the valve cover (3a2), and the other end abuts against the blocking portion (4a). The hollow valve core (4) reciprocates along the axial direction of the cylinder body (2), which can cause the reset member (5) to undergo elastic deformation.

7. The constant pressure device of the nail gun according to claim 6, characterized in that The reset member (5) is sleeved on the hollow valve core (4); one end of the valve seat (3a1) is provided with an internal thread and an external thread; the axes of the internal thread and the external thread coincide with the axis of the hollow valve core (4).

8. The constant pressure device of the nail gun according to claim 7, characterized in that: The rotation direction of the internal thread is the same as or opposite to that of the external thread.

9. The constant pressure device of the nail gun according to claim 8, characterized in that: One side of the external thread can abut against the valve cover (3a2), and the other side is provided with a thread groove, a sealing ring (6) is sleeved on the thread groove, and a groove (2a1) for accommodating the sealing ring (6) is provided on the cylinder head (2a).

10. The constant pressure device of the nail gun according to claim 1, characterized in that: The piston (2b) is provided with a firing pin (1a), and the nail gun is provided with a lifter (1b1), and the lifter (1b1) drives the piston (2b) to move through the firing pin (1a) until the pressure in the chamber (2c) reaches the threshold value.

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