Automatic tightening method for round nut

Abstract

The invention relates to an automatic round nut tightening method which is characterized in that a flexible nut clamping seat (2) is used for clamping a nut (1), the flexible nut clamping seat (2) comprises a flexible chuck (21) and a supporting column (22), the supporting column (22) is connected to the lower surface of the flexible chuck (21), the flexible chuck (21) is a short cylinder, a cylindrical groove (211) is formed in the center of the flexible chuck (21), and the cylindrical wall of the cylindrical groove (211) is made of a flexible material; the method has the beneficial effects that the method is novel and ingenious, the steps are simple, simple and reliable, materials involved in the method are common and low in cost, the involved device is simple in structure, and a power part is a common power source of a tightening tool.

Description

Technical Field

[0001] The invention relates to an automatic tightening method for round nuts, belonging to the field of automatic assembly mechanical equipment. Background Art

[0002] As a common mechanical connection fastener, round nuts are often used in the connection and fastening structure of mechanical assembly. Compared with the outer hexagonal nut, which can be fixed with a rigid sleeve to achieve automatic tightening, since the outer surface of the round nut itself is a cylindrical surface without edges and corners, it is difficult to use a rigid sleeve to fix and clamp it, and it is not easy to achieve automatic tightening. Moreover, most miniature round nuts do not have a slot on the end face, and the round nut cannot be tightened by inserting a tightening tool into the end face slot, and automatic tightening cannot be achieved. Therefore, the method of tightening round nuts used in patent CN105922181A cannot be used for round nuts without slots. At present, the tightening of round nuts without slots is all done by manual tightening, that is, the friction torque between the fingers and the round nut is used to provide the screwing power, and finally the round nut is tightened.

[0003] Round nuts are common fasteners in the mechanical assembly of industrial products, with a wide range of applications and large quantities. Tightening round nuts by hand alone is difficult to meet the needs of large-scale industrial assembly, and the consistency of the tightening torque is difficult to ensure. Therefore, a method for automatically tightening round nuts is proposed, which can improve assembly efficiency and achieve torque quality consistency. Summary of the invention

[0004] The purpose of the present invention is to provide an automatic tightening method for round nuts, which is suitable for automatic screwing and assembly of all types of round nuts, especially for automatic tightening of miniature round nuts without slots, so as to solve the problem of lack of automatic tightening method and device for round nuts in the prior art.

[0005] A method for automatically tightening round nuts, characterized in that a nut 1 is clamped by a flexible nut clamping seat 2, wherein the flexible nut clamping seat 2 comprises a flexible chuck 21 and a support column 22, the support column 22 is connected to the lower surface of the flexible chuck 21, the flexible chuck 21 is a short cylinder, and a cylindrical groove 211 is provided at the center thereof, and the cylindrical wall of the cylindrical groove 211 is made of a flexible material; the method comprises the following steps:

[0006] Step 1: Press the round nut 1 to be installed into the cylindrical groove 211 of the flexible nut clamping seat 2;

[0007] Step 2: Connect the rotating power device 7 to the support column 22 of the flexible nut clamping seat 2, and insert the screw 3 into the connected part 4; and place the screw 3 with the connected part 4 on the upper part of the round nut 1;

[0008] Step 3: The rotating power device 7 drives the nut clamping seat 2 to rotate and move upward; the round nut 1 clamped by the nut clamping seat 2 is rotated and screwed onto the outside of the screw 3.

[0009] Among them, the diameter of the cylindrical groove 211 of the flexible nut clamping seat 2 described in step one is smaller than the diameter of the round nut 1, so that the round nut 1 and the cylindrical groove 211 of the flexible nut clamping seat 2 have an interference fit.

[0010] In the step 2, the rotating power device 7 and the support column 22 of the flexible nut clamping seat 2 are connected together through a one-way clutch. The one-way clutch is divided into two parts: an upper clutch 5 and a lower clutch 6. The upper clutch 5 is connected to the flexible nut clamping seat 2, and the lower clutch 6 is connected to the rotating power device 7.

[0011] The clutch end surfaces of the clutch upper part 5 and the clutch lower part 6 are in a sawtooth shape.

[0012] The flexible nut clamping seat 2 described in step 2 is installed on the turntable 8, and the round nut 1 is pressed into the flexible nut clamping seat 2 through the multi-station turntable rotation, that is, the first station realizes the pressing process, and the turntable 8 rotates to the second station, and the second station is the tightening process.

[0013] The elastic material used for the round nut clamping seat 2 can be one or a composite material mixed together of rubber, silicone rubber, polyurethane, and latex.

[0014] The flexible clamping head 21 and the supporting column 22 of the round nut clamping seat 2 are integrated and made of flexible material.

[0015] The outer wall and bottom of the flexible clamp 21 of the round nut clamping seat 2 are made of metal material 201, and the ring in the middle is made of flexible material 202.

[0016] The support column 22 is a solid cylinder with a through hole in the middle or a blind hole on the upper surface of the cylinder.

[0017] Beneficial effects:

[0018] The beneficial effects of the present invention are that the method is novel and ingenious, the steps are concise, simple and reliable, the materials involved in the method are relatively common and low-cost, the device structure is simple, and the power part is a common power source for tightening tools. The automatic tightening method for round nuts can be applied to the automatic tightening device part of round nuts of automatic assembly machines in the automated assembly industry, and can replace the work process of manually tightening nuts, reduce the labor intensity of workers, and improve production efficiency and consistency of tightening torque. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 , is a schematic diagram of the pressing process of the round nut 2 of the present invention; wherein,

[0020] (a) A schematic diagram of the round nut 2 and the flexible nut clamping seat 2 of the present invention being separated;

[0021] (b) A schematic diagram of the state when the round nut 2 of the present invention is pressed into the cylindrical groove 211 of the flexible nut clamping seat 2;

[0022] Figure 2 , is a schematic diagram of the nut screwing process of the present invention; wherein,

[0023] (a) A schematic diagram of a screw 3 of the present invention being above a flexible nut clamping seat 2 on which a round nut 1 is pressed;

[0024] (b) A schematic diagram of the process in which the flexible nut holder 2 of the present invention drives the round nut 1 to rotate so that the round nut 1 is screwed onto the screw 3;

[0025] (c) Schematic diagram of the state when the round nut 1 is screwed onto the screw 3 and the flexible nut clamping seat 2 is removed.

[0026] Figure 3 , is a schematic diagram of the screwing action of the round nut 2 of the turntable structure of the invention; wherein,

[0027] (a) A schematic diagram of the flexible nut clamping seat 2 on the turntable of the present invention before being connected to the rotary power device 7;

[0028] (b) A schematic diagram of the state after the flexible nut clamping seat 2 on the turntable of the present invention is connected to the rotary power device 7;

[0029] Figure 4 , a schematic structural diagram of the flexible nut clamping seat 2 of the present invention;

[0030] Figure 5 , a schematic structural diagram of the flexible chuck 21 and the support column 22 of the flexible nut clamping seat 2 of the present invention, which are integrated and made of flexible material;

[0031] Figure 6 , a schematic structural diagram of the flexible nut clamping seat 2 of the present invention being made of a flexible material 202 and a metal material 201;

[0032] Figure 7 , a schematic structural diagram showing that the support column 22 of the flexible nut clamping seat 2 of the present invention is a solid cylinder.

[0033] Among them, 1 is a round nut, 2 is a flexible nut clamping seat, 3 is a screw, 4 is a connected part, 5 is an upper part of a clutch, 6 is a lower part of a clutch, 7 is a power device, 8 is a turntable, 21 is a flexible chuck, 22 is a support column, 211 is a cylindrical groove, 201 is a metal material, and 202 is a flexible material 202. DETAILED DESCRIPTION

[0034] The invention discloses an automatic tightening method for round nuts. The first step is to press the round nut into a nut clamping seat. The second step is to rotate a power device to drive the flexible nut clamping seat and the round nut to rotate together and move axially to screw the round nut into a corresponding screw rod.

[0035] The method described in the present invention includes a round nut clamping seat having a clamping function for round nuts. The round nut clamping seat has a flexible (elastic) structure, or is composed of a flexible (elastic) material. The diameter of the concave hole of the round nut clamping seat is slightly smaller than the size of the round nut.

[0036] One structure of the round nut clamping seat is an elastic collet made of metal material or polymer and its composite material.

[0037] The elastic material used for the round nut clamping seat can be elastic polymers such as rubber, silicone rubber, polyurethane, latex, and their composite materials.

[0038] In the method, the nut clamping seat and the rotary power device are connected via a single-direction clutch.

[0039] The one-way clutch is divided into two parts, the upper part is connected with the round nut clamping seat, and the lower part is connected with the rotating power device. The disengageable end surfaces of the upper and lower parts of the one-way clutch are in a sawtooth form.

[0040] The steps of pressing and screwing the round nut are implemented by a multi-station turntable rotation, wherein the first station implements the pressing process and the second station is the tightening process.

[0041] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments to help understand the content of the present invention.

[0042] like Figure 1, 2 and 3, the present invention provides a method for automatically tightening round nuts. In the first step, the round nut 1 is pressed into the nut clamping seat 2. In the second step, the rotating power device 7 drives the flexible nut clamping seat 1 and the round nut 1 to rotate together, and makes axial movement, and screws the round nut 1 into the screw of the corresponding screw 3. The round nut clamping seat 2 includes a flexible (elastic) structure, or is composed of a flexible (elastic) material. The structure of the round nut clamping seat 2 can be an elastic collet made of metal material or polymer and its composite material, or can be a polymer and its composite material with elasticity such as rubber, silicone rubber, polyurethane, latex, etc. The diameter size of the concave hole of the round nut clamping seat 2 is slightly smaller than the size of the round nut 1. At the same time, because the round nut clamping seat 2 includes a flexible (elastic) structure, or is composed of a flexible (elastic) material, when the round nut 1 is pressed into the concave hole of the round nut clamping seat 2, it will not be subject to much resistance. After the round nut 1 is pressed into the nut holder 2, the rotating power device 7 drives the flexible nut holder 2 and the round nut 1 to rotate together and move axially to screw the round nut 1 into the screw of the corresponding screw 3. Figure 2 As shown in (b), the connected component 4 is tightened after the round nut 1 is screwed until it contacts the bottom surface of the connected component 4. Figure 2 As shown in (c), after the round nut 1 is tightened, the round nut clamping seat 2 moves downward to make the round nut 1 disengage from the concave hole of the round nut clamping seat 2.

[0043] Usually, the steps of pressing and screwing the round nut 1 are implemented by a multi-station turntable rotation, where the first station implements the pressing process and the second station is the tightening process. Figure 3 As shown in (a), at this time, the nut clamping seat 2 at the left station of the turntable 8 has no round nut 1 pressed in, while the nut clamping seat 2 at the right station has a round nut 1 pressed in. Below the left station of the turntable 8 is a rotating force device 7 that can perform a linear upward movement. The nut clamping seat 2 and the rotating power device 7 are connected by a one-way clutch. The one-way clutch is divided into two parts, the upper part 5 of the one-way clutch is connected to the round nut clamping seat 2, and the lower part 6 of the one-way clutch is connected to the rotating power device 7. Since the disengageable end surfaces of the upper and lower parts 5 and 6 of the one-way clutch are serrated, the round nut clamping seat 2 can realize the function of unidirectional rotation under the drive of the rotating power device 7. As shown Figure 3 As shown in (b), the state at this time is Figure 3(a) The turntable 8 rotates 180 degrees around the axis, the nut clamping seat 2 at the left station has the round nut 1 pressed in, the nut clamping seat 2 at the right station has no round nut 1 pressed in, and the round nut clamping seat 2 moves up together with the round nut 1, the clutch upper part 5, the clutch lower part 6 and the rotating power device 7. This state is illustrated as the moment when the round nut 1 has not yet contacted the screw 3 during the screwing process. When the left station completes the screwing of the round nut 1 onto the screw 3, the round nut clamping seat 2 moves down together with the clutch upper part 5, the clutch lower part 6 and the rotating power device 7 to achieve the disengagement of the round nut 1 from the round nut clamping seat 2 and the separation of the clutch upper part 5 from the clutch lower part. During the downward movement of the left station, the right station can complete the pressing of the round nut 1 into the nut clamping seat 2. At this time, the states of each component are the same as Figure 3 (a) The state of the components is consistent. This turntable component structure is often used in the automatic tightening process of round nuts of turntable automatic assembly machines in the automated assembly industry. Figure 3 (a) with Figure 3 The process described in (b) is carried out sequentially to complete the automatic screwing process of a large number of round nuts in the assembly line production.

[0044] The above-described embodiments are only preferred embodiments of the present invention. It should be noted that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

[0045] The present invention discloses a method for automatically tightening round nuts, which can realize tightening the round nuts with a certain torque without damaging the outer surface of the round nuts, and belongs to the technical field of automatic assembly equipment. Round nuts are a common mechanical fastener, and unslotted round nuts are difficult to automatically tighten because their appearance is difficult to effectively cooperate with conventional rigid tightening tools to transmit tightening torque. The present invention provides a method for automatically tightening round nuts. The present invention first presses the round nut into a flexible nut clamping seat, and then drives the flexible nut clamping seat and the round nut to rotate together with a rotating power device, so as to screw the round nut into the corresponding screw. This method for automatically tightening round nuts is applied to the tightening mechanism device of a round nut automatic assembly machine.

[0046] 1. The present invention provides a method for automatically tightening round nuts. The first step is to press the round nut into a nut clamping seat. The second step is to drive the flexible nut clamping seat and the round nut to rotate together and move axially to screw the round nut into a corresponding screw.

[0047] 2. The method described in the present invention includes a round nut clamping seat having a clamping function for the round nut. The round nut clamping seat has a flexible (elastic) structure, or is composed of a flexible (elastic) material. The diameter of the concave hole of the round nut clamping seat 2 is slightly smaller than the size of the round nut.

[0048] 3. One structure of the round nut clamping seat is an elastic collet made of metal material or polymer and its composite material.

[0049] 4. The elastic material used for the round nut clamping seat can be elastic polymers such as rubber, silicone rubber, polyurethane, latex, and their composite materials.

[0050] In the method, the nut clamping seat and the rotary power device are connected via a single-direction clutch.

[0051] 6. The one-way clutch is divided into two parts, the upper part is connected to the round nut clamping seat, and the lower part is connected to the rotating power device. The disengageable end surfaces of the upper and lower parts of the one-way clutch are in a serrated form.

[0052] The steps of pressing and screwing the round nut are implemented by a multi-station turntable rotation, wherein the first station implements the pressing process and the second station is the tightening process.

Claims

1. A method for automatically tightening round nuts, characterized in that: A nut (1) is clamped by a flexible nut clamping seat (2), wherein the flexible nut clamping seat (2) comprises a flexible clamping head (21) and a support column (22), the support column (22) is connected to the lower surface of the flexible clamping head (21), the flexible clamping head (21) is a short cylinder, the center of which has a cylindrical groove (211), and the cylindrical wall of the cylindrical groove (211) is made of a flexible material; the method comprises the following steps: Step 1: Press the round nut (1) to be installed into the cylindrical groove (211) of the flexible nut clamping seat (2); Step 2: Connect the rotary power device (7) to the support column (22) of the flexible nut clamping seat (2), and insert the screw (3) into the connected component (4); and place the screw (3) with the connected component (4) on the upper part of the round nut (1; Step 3: The rotating power device (7) drives the nut clamping seat (2) to rotate and move upward; the round nut (1) clamped by the nut clamping seat (2) is rotated and screwed onto the outside of the screw (3).

2. The method for automatically tightening round nuts according to claim 1, characterized in that: The diameter of the cylindrical groove (211) of the flexible nut clamping seat (2) described in step 1 is smaller than the diameter of the round nut (1), so that the round nut (1) and the cylindrical groove (211) of the flexible nut clamping seat (2) are interference fit.

3. A method for automatically tightening round nuts according to claim 1 or 3, characterized in that: In the step 2, the rotating power device (7) and the support column (22) of the flexible nut clamping seat (2) are connected together through a one-way clutch, and the one-way clutch is divided into two parts: an upper clutch part (5) and a lower clutch part (6), wherein the upper clutch part (5) is connected to the flexible nut clamping seat (2), and the lower clutch part (6) is connected to the rotating power device (7).

4. A method for automatically tightening round nuts according to claim 3, characterized in that: The clutch end surfaces of the clutch upper part (5) and the clutch lower part (6) are in a sawtooth shape.

5. A method for automatically tightening round nuts according to claim 3, characterized in that: The flexible nut clamping seat (2) described in step 2 is installed on a turntable (8), and the round nut (1) is pressed into the flexible nut clamping seat (2) through a multi-station turntable rotation, that is, the first station realizes the pressing process, and the turntable 8 rotates to the second station, and the second station is the tightening process.

6. A method for automatically tightening round nuts according to claim 1 or 2, characterized in that: The elastic material used in the round nut clamping seat (2) can be one or a composite material of rubber, silicone rubber, polyurethane, latex, or a mixture of the two or more.

7. A method for automatically tightening round nuts according to claim 1 or 2, characterized in that: The flexible clamp (21) and the support column (22) of the round nut clamping seat (2) are integrated and made of flexible material.

8. A method for automatically tightening round nuts according to claim 1 or 2, characterized in that: The flexible clamp (21) and the outer wall and the bottom of the round nut clamping seat (2) are made of metal material (201), and the middle ring is made of flexible material (202).

9. A method for automatically tightening round nuts according to claim 1 or 2, characterized in that: The support column (22) is a solid cylinder with a through hole in the middle of the cylinder or a blind hole on the upper surface of the cylinder.

Images