CN112357521B

CN112357521B - Directional transmission method and device suitable for L valve rod

Info

Publication number: CN112357521B
Application number: CN202011197049.2A
Authority: CN
Inventors: 韩良; 刘健均
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2020-10-31
Filing date: 2020-10-31
Publication date: 2022-06-07
Anticipated expiration: 2040-10-31
Also published as: CN112357521A

Abstract

The invention relates to the field of automatic processing of L-shaped valve rods, in particular to a directional transmission method and a directional transmission device suitable for the L-shaped valve rods. The directional transmission device suitable for the L valve rod sets the movement mode of the hopper, increases the torsional movement in the vibration or up-and-down movement process of the traditional hopper, the L valve rod ascends along the spiral trough in the hopper under the comprehensive action of inertia force, gravity and friction force, the L valve rod and the disc do upward torsional movement together, and when the vertical component of the inertia force borne by the L valve rod is greater than the gravity acceleration, the L valve rod jumps upwards along the spiral groove of the disc; when the vertical component is smaller than the gravity acceleration, the L valve rod overcomes the friction force to slide upwards along the spiral groove, the L valve rod has the process of jumping upwards along the disc spiral groove and the process of overcoming the friction force to slide upwards along the spiral groove by the movement, the L valve rod slides into the material groove in the movement process, and the automatic orientation of the L valve rod is completed.

Description

Directional transmission method and device suitable for L valve rod

Technical Field

The invention belongs to the technical field of industrial automatic transmission, and particularly relates to a novel rapid automatic directional transmission technology for an L-shaped valve rod.

Background

Whether the operation of the production line is normal or not directly influences the production progress, the production efficiency and the production cost. The production line which runs well and is adjusted and optimized can greatly improve the production efficiency and eliminate the obstacles among all processing links in the production process of enterprises.

Workpiece feeding and discharging are a key ring of a production line, and the feeding and discharging speed directly influences the production efficiency of the whole production line. The optimized adjustment of the workpiece feeding and discharging equipment enables the production line to be further upgraded, the adjustment of the direction of unmanned and automatic operation is changed, the productivity is further liberated, and the production efficiency is improved. The spraying equipment is applied to production and living aspects, such as disinfection spraying, dust removal spraying, landscaping spraying and the like.

Wherein the L-valve stem is a key component of the spray device. As shown in fig. 5, the L-shaped valve rod has a small size and a special shape, and the L-shaped valve rod cannot accurately enter the material tank by using conventional hopper conveying and slight vibration; in the conveying process of the L-shaped valve rod, due to the existence of the smooth lower-end circular tube, the L-shaped valve rod provided with the large-head connecting section is easy to rotate and translocate in the conveying process; simultaneously, because of there must have the clearance between silo and the L valve rod, consequently the L valve rod is at the roll in-process, and the slope of inevitable rotates, when L valve rod diagonal is close or is less than silo cross-section width, has to be blocked or loses directional danger.

However, due to production requirements, the L-shaped valve rods need to be arranged according to a specific posture and scale during feeding so as to complete the subsequent processing link of the workpiece; consequently, lead to current L valve rod can't rely on the machine to carry out stable transmission, need artifical the correction after, place on conveyor.

Causing great labor intensity of workers and being not suitable for modern production. Meanwhile, the L-shaped valve rod is small in structure and irregular in shape, so that the requirement on the operation level of workers is high. The worker is tedious to operate repeatedly, and the attention is easy to disperse, so that the product accuracy is low and the qualification rate is low.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: the invention aims to overcome the defects in the prior art and provides a directional transmission method and a directional transmission device which are high in transmission speed and high in efficiency and are suitable for an L valve rod.

The technical scheme of the invention is as follows: the directional transmission method applicable to the L-shaped valve rod comprises a hopper and a hopper driving module for driving the hopper to move up and down; a spirally-rising material groove is arranged along the inner wall of the hopper;

the hopper driving module can drive the hopper to perform torsional motion in the motion process from the lowest point to the highest point, and drives the L-shaped valve rod in the hopper to enter the trough and output along the trough.

Further, the device comprises a hopper and a hopper driving module; a trough spirally rising along the inner wall of the hopper is arranged in the hopper, and the outlet end of the trough is connected with a valve rod transmission mechanism;

the hopper driving module comprises an armature block and a base which are arranged below the hopper; the base is connected with the armature block through a plate spring; an inclination angle is arranged between the plate spring and the seat; and the base is provided with a traction device for driving the armature block to descend. Furthermore, the traction device is an electromagnet, and the pulse voltage of half-wave rectification is introduced into the traction device;

in the 1/4 period when the current is from zero to the peak value, the attraction force of the traction device is gradually increased, the armature block drives the hopper to move downwards, and the plate spring is bent and deformed;

when the current is in the period from peak value to zero, the armature block is driven to rotate upwards under the action of the plate spring.

Further, the traction device is an air cylinder or an oil cylinder.

The invention also comprises a directional transmission device suitable for the L-shaped valve rod, which comprises a hopper, a hopper driving module and a valve rod transmission mechanism, wherein the hopper driving module drives the hopper to move up and down; a spirally-ascending trough is arranged on the inner wall of the hopper; the outlet end of the material groove is connected with a valve rod transmission mechanism.

Further, the valve rod transmission mechanism comprises a transmission pipe, and the width B of the pipeline groove of the transmission pipe is L + e;

in the formula, B represents the width of a transmission pipe groove; l is the workpiece length of the valve rod; D-L workpiece width of the valve rod; e, a gap between the end face of the L valve rod and the inner wall of the transmission pipe; a horizontal included angle θ; a friction angle ρ; theta is the included angle between the diagonal C of the workpiece and the horizontal plane of the inner wall of the transmission pipe; rho is the included angle between the reaction force N of the inner wall of the transmission pipe and the horizontal plane of the inner wall of the transmission pipe when the valve rod rotates obliquely and touches the inner wall of the transmission pipe in the rolling process.

Further, the hopper comprises a left hopper and a right hopper; the valve rod transmission mechanism comprises a left channel butted with the left hopper and a right channel butted with the right hopper; counting sensors are arranged at the outlets of the left channel and the right channel;

a left moving channel is arranged at the discharge port of the left channel; a right moving channel is arranged at the discharge port of the right channel; the left moving channel and the right moving channel can butt the discharge port of the moving channel with the material inlet of the valve rod fixing piece counting channel under the action of the pneumatic device.

Has the advantages that:

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

1. setting a hopper motion mode, increasing the torsional motion of the vibration or up-and-down motion process of the traditional hopper, enabling the L valve rod to ascend along a spiral trough in the hopper under the comprehensive action of inertia force, gravity and friction force, enabling the L valve rod and the disc to do upward torsional motion together, and enabling the L valve rod to jump upwards along a disc spiral groove when the vertical component of the inertia force borne by the L valve rod is larger than the acceleration of gravity; when the vertical component is smaller than the gravity acceleration, the L valve rod overcomes the friction force to slide upwards along the spiral groove, the L valve rod has the process of jumping upwards along the disc spiral groove and the process of overcoming the friction force to slide upwards along the spiral groove by the movement, the L valve rod slides into the material groove in the movement process, and the automatic orientation of the L valve rod is completed.

2. The automatic L valve rod positioning and conveying device is convenient and simple to operate, the L valve rod positioning and conveying are automatically completed, manual positioning of the L valve rod is not needed, the accuracy is improved, automatic conveying is achieved, the device is low in production cost, compact in structure, high in conveying speed and high in efficiency, replacement and upgrading are easily carried out on the existing production line, and the production efficiency is further improved.

3. Aiming at the L valve rod, the shape and the size of the cross section of the channel groove and the arc shape of the channel are accurately designed, so that the L valve rod is prevented from rotating, being clamped and the like in the transmission process. The spiral ascending trough is arranged along the inner wall of the hopper, a power device is not needed, and the structure is simple. In order to ensure that the workpiece passes through the raceway smoothly without losing the orientation state.

Drawings

FIG. 1 is an overall structural view of an L-stem transfer device;

FIG. 2 is a detailed block diagram of the hopper and the hopper drive module;

FIG. 3 is a detailed block diagram of the rapid transfer mechanism;

FIG. 4 is a channel slot sizing diagram;

FIG. 5 is a detailed structural view of the L-stem;

fig. 6 is a cross-sectional view of fig. 4.

Detailed Description

For the understanding of the present invention, the following detailed description will be given with reference to the accompanying drawings, which are provided for the purpose of illustration only and are not intended to limit the scope of the present invention.

Fig. 1-4 show the directional transmission device of the L-shaped valve rod of the invention, which adopts a left and right symmetrical design, and the inner wall of the hopper 1 is provided with a spiral ascending trough 10; the outlet end of the trough 10 is connected with a valve rod transmission mechanism 3.

The hopper 1 comprises a left hopper 1-1 and a right hopper 1-2; the valve rod transmission mechanism 3 comprises a left channel 3-1 butted with the left hopper 1-1 and a right channel 3-2 butted with the right hopper 1-2; counting sensors 5 are arranged at the outlets of the left channel 3-1 and the right channel 3-2;

a discharge port of the left channel 3-1 is provided with a left moving channel 41; a discharge port of the right channel 3-2 is provided with a right moving channel 42; the left moving channel 41 and the right moving channel 42 can butt the discharge port of the moving channel to the feed port of the valve rod fixing piece counting channel 6 under the action of a pneumatic device.

The hardware part comprises a hopper 1, a transmission pipe 30 matched with the L valve rod, a movable vertical plate 32, a sensor 5, a pneumatic device, a display and control device 7, a fixed frame 8 and the like. The display and control device 7 comprises vibration control of the hopper 1 and the vibrating hopper, motion control of an air cylinder, sensor data acquisition, communication and the like.

The main function of the hopper 1 vibration hopper is to directionally sort the L valve rods 9, so that the disordered L valve rods 9 are sequentially transmitted in a certain direction.

The hopper driving module 2 is externally provided with a cover 27, the hopper driving module 2 consists of 4 groups of plate springs 23, 4

angle joints

26, 1

armature block

21, 1 base 22 and a pulling device 24, wherein the pulling device 24 is preferably an electromagnet and consists of 1E-shaped iron core and 1 coil.

The messy L-stem 9 stored in the middle of the hopper 1 can be transported and oriented in sequence along the trough 10. The E-core holds the coil and is fastened to the center of the base 22 by means of socket head cap screws. The base 22, the angle joint, the plate spring 23 and the armature block 21 are tightly connected through the hexagon socket head cap screw in sequence. The leaf springs 23 are mounted at an angle to connect the angle joint and the armature block 21 at an appropriate angle of inclination.

When alternating current is introduced into the coil, a magnetic circuit is formed between the iron core and the armature block 21, the iron core attracts the armature block 21 to drive the hopper 1, and the plate spring 23 converts the up-and-down reciprocating motion with small amplitude and high frequency into the reciprocating micro-torsion motion, namely the armature block 21 simultaneously performs the up-and-down and torsion motions.

The hopper 1 is fixed to the armature block 21 plate so as to generate the same vibration. The L valve rod 9 ascends along a spiral track in the hopper 1 under the comprehensive action of inertia force, gravity and friction force, completes automatic orientation of the L valve rod 9 in the ascending process, and enters a transmission channel from a discharge port to achieve the functions of orientation and transmission of the L valve rod 9.

When the half-wave rectified pulsating voltage is introduced into the coil, the attraction force is gradually increased in the period from zero to the peak value of the current, the armature block 21 drives the hopper 1 to move downwards, and the plate spring 23 is bent and deformed.

During the period from peak value to zero, under the action of the plate spring 23, the armature block 21 is subjected to an obliquely upward resultant force, which can be divided into a vertical component and a tangential component, wherein the vertical component enables the hopper 1 to move upward, the tangential component enables the hopper 1 to rotate, and the hopper 1 rotates upward under the combined action.

The transfer and orientation of the L-valve stem 9 in the vibrating hopper occurs during the upward movement phase of the hopper 1, i.e. during the phase of the return deformation of the leaf spring 23. The L valve rod 9 can move on the hopper 1 in different forms by adjusting the vibration parameters and the mounting position of the system, and jump and smooth upwards along the spiral groove.

Under the action of the restoring force of the plate spring 23, the L valve rod 9 and the hopper 1 do upward torsional movement together;

when the vertical component of the inertia force borne by the L valve rod 9 is larger than the gravity acceleration, the L valve rod 9 jumps upwards along the spiral groove of the hopper 1;

when the vertical component is smaller than the acceleration of gravity, the L-valve rod 9 slides upward along the spiral groove against the frictional force.

In the downward movement stage of the hopper 1, if the L valve rod 9 makes jumping movement, the L valve rod 9 is not contacted with the hopper 1, the parameters can be adjusted to realize that the time interval of the landing point of the L valve rod 9 corresponds to the vibration period of the hopper 1, so that the L valve rod 9 continuously jumps upwards along the spiral groove;

if the L-valve rod 9 makes a smooth movement, it may be stationary or slide down a distance, depending on the combined effect of the inertial force, frictional force and gravity.

The plate spring 23 in the vibrating hopper is composed of a plurality of plate springs. The resonance adjustment can be realized by changing the thickness of the plate spring or increasing or decreasing the number of the plate springs. Because the rigidity of the plate springs 23 is greatly different in different bending directions, high precision and consistency of the four groups of plate springs 23 need to be ensured during installation, otherwise, normal work of the hopper is influenced.

Further, the plate springs 23 are inclined in the opposite direction to the rising angle of the spiral groove 10, and four sets of plate springs 23 are uniformly installed on the base along the circumference at the same inclination angle.

The vibration frequency and the amplitude of the vibration hopper can be adjusted by a corresponding controller, and the proper vibration frequency and amplitude are selected according to the physical properties and the working conditions of the workpiece.

The valve rod transmission mechanism 3 comprises a transmission pipe 30, and the transmission pipe 30 has a pipeline width; (ii) a

In the formula, B-the cross section groove width of the transmission pipe; l is the workpiece length of the valve rod; D-L workpiece width of the valve rod; e, a gap between the end face of the L valve rod and the inner wall of the transmission pipe; a horizontal included angle θ; a friction angle ρ; theta is the included angle between the diagonal C of the workpiece and the horizontal plane of the inner wall of the transmission pipe; rho is the included angle between the reaction force N of the inner wall of the transmission pipe and the horizontal plane of the inner wall of the transmission pipe when the valve rod rotates obliquely and touches the inner wall of the transmission pipe in the rolling process.

As shown in dashed lines in fig. 4. When the L valve rod touches the trough, a moment consisting of a reaction force N and a force arm alpha is generated, so that the workpiece tends to rotate continuously. The larger the value of e, the larger the rotation angle. When the workpiece diagonal C is close to or less than the raceway width B, the workpiece risks becoming stuck or becoming disoriented.

The gap is thus dimensioned so that when turned into contact with the side wall, its diagonal C makes an angle theta with the horizontal which is greater than the angle of friction rho. In this case, the moment formed by the reaction force N and the force arm can prevent the workpiece from rotating, so that the workpiece can be smoothly conveyed according to a correct orientation state. From the geometrical relationships in fig. 4, the following dimensional relationships can be derived:

according to the limiting conditions:

the allowable peak gap is obtained:

wherein μ —, the coefficient of sliding friction between the workpiece and the sidewall, μ ═ 0.1 to 0.5, and D — L, the workpiece width (mm) of the valve stem.

For example, the maximum dimension of the L-stem 9 workpiece is used for calculation during design, i.e., L is 31.5mm and D is 25 mm. The following can be obtained:

the center of gravity of the L valve rod 9 is determined to be at the large end 90 according to the particularity of the shape of the workpiece, and in addition, the small end 91 is longer than the large end, so that the L valve rod 9 can rotate clockwise in the trough 1010, and the orientation and the sequencing of the L valve rod 9 can be damaged.

Therefore, the profiling trough 10 can be designed according to the characteristics of the size end of the L valve rod 9, the internal hole pattern of the trough 1010 is consistent with that of the L valve rod 9, the L valve rod 9 is prevented from rotating in the conveying process of the trough 1010, and the directivity of the L valve rod 9 is kept.

Meanwhile, in order to enable the L-shaped valve rod 9 workpiece to smoothly enter another workpiece channel section from one workpiece channel section, the outlet and the inlet of each workpiece channel are designed to be trumpet-shaped.

The valve rod transmission mechanism 3 comprises a fixed vertical plate 31 and a movable vertical plate 32 arranged on the fixed vertical plate 31, the movable vertical plate 32 comprises a left movable vertical plate and a right movable vertical plate, and a left channel 3-1, a right channel 3-2 and a corresponding cylinder connecting piece are respectively arranged on the left movable vertical plate and the right movable vertical plate.

Specifically, a left moving channel 41 is arranged on the right side of the left moving vertical plate, and the left side of the left moving vertical plate is connected with a left air cylinder push rod through a connecting piece; the left side of the right moving vertical plate is provided with a right moving channel 42, and the right side of the right moving vertical plate is connected with a right cylinder push rod through an adapter.

The moving vertical plate 32 can move left and right smoothly under the driving of the left and right telescopic driving of the cylinder push rod. To ensure an accurate fit of the workpiece path, the range of motion and the scram position of the moving riser 32 need to be precisely defined by the locating block 21. Before the device touches the positioning block 21, the device touches the oil buffer to decelerate, so that the vibration and noise generated when the moving vertical plate suddenly stops are reduced, and the device can continuously work under a stable condition. Meanwhile, each movable vertical plate 32 is arranged on an upper linear guide rail and a lower linear guide rail, and the linear guide rails are horizontally arranged to assist the movable vertical plates 32 to move left and right.

Wherein, the movable vertical plate is formed by processing an aluminum plate and is shaped like a Chinese character 'hui'. Both the weight of the device can be reduced and the design can be made more compact. The movement of each moving riser is limited by 4 stops 21 and 4 oil buffers reduce the shock. The 4 limiting blocks 21 and the 4 oil buffers are arranged on the fixed frame of the fixed vertical plate 31 and are positioned on the inner side of the movable vertical plate.

The counting sensors 5 are optical fiber sensors, 3 in total, and are arranged at the outlets of the left channel 3-1 and the right channel 3-2 and the material inlet of the valve rod fixing counting channel 6 and used for judging the position of the L valve rod 9 and counting the number. The model is BF-5R-D1-N type digital optical fiber sensor and FD-320-05 optical fiber head of AUTONICS. This sensor can detect up to 2 ten thousand times per second and has a resolution of 1/10000. The light source adopts red LED modulated light to be transmitted to the optical fiber head through the optical fiber, the intensity of the light is changed due to the interaction of the modulated light and the workpiece to be detected, the light receiving quantity is calculated through signal processing and is compared with a set threshold value, the value of the light reflecting quantity of the workpiece is larger than the set threshold value within a certain distance from the workpiece to the optical fiber head of the sensor, and therefore the workpiece reaches a specified position and is fed back to the controller through a feedback signal.

The pneumatic device for driving the movable vertical plate 32 to move smoothly left and right comprises an air cylinder, an air compressor, an air circuit and the like.

Wherein, the cylinder selects a standard high-thrust cylinder, the stroke is 50mm, the use pressure range is 0.1-1.0 MPa, and the use speed range is 30-800 mm/s. The thrust and the using speed meet the requirements. The expansion and contraction of the cylinder are controlled by a control system. When the sensor detects that the workpiece reaches the designated position and is full, the sensor generates a signal to the control system, and the control system executes corresponding switching action on the electromagnetic valve according to the signal, so that the air passage of the electromagnetic valve is switched on or off to further control the corresponding air cylinder to stretch.

The fixed frame of the directional transmission device of the L valve rod is constructed by adopting industrial aluminum profiles and aluminum plates and is connected with a connecting corner piece through a bolt hole. Compared with the traditional mechanical structure, the industrial aluminum profile has the following advantages: the aluminum profile has better rigidity and strength; the density is small, the weight is light, and the surface is treated, so that the appearance effect and the corrosion resistance are better; the shape and the size are standardized, and optional standard connecting pieces are diversified; the assembly precision is high, easy dismounting, can used repeatedly.

The control system of the directional transmission device of the L-shaped valve rod comprises vibration control of the electromagnetic hopper 1 vibration hopper, motion control of an air cylinder, sensor data acquisition and communication and the like. The central processing unit of the control system is an ohm dragon PLC with the model number of CP 1E. The PLC has high cost performance, can flexibly support a small system, has rich optional equipment, high expansibility and reliability and high resolution of 1/12000, and realizes high-precision analog input and output control. Compared with other single-chip microcomputers and microcontrollers, the PLC has higher reliability, and is internally provided with a photoelectric isolation circuit, so that the anti-interference capability is improved.

The specific implementation mode of the device is as follows:

the L valve rods 9 to be conveyed in the sequencing direction are placed into the left hopper and the right hopper, the left hopper 1-1 and the right hopper 1-2 simultaneously arrange and orient the L valve rod workpieces, and the L valve rods 9 are conveyed to the valve rod conveying mechanism 3. The valve rod transmission mechanism consists of a left channel 3-1 butted with the left hopper 1-1, a right channel 3-2 butted with the right hopper 1-2, two movable vertical plates 32 and a valve rod connecting fixed piece counting channel 6. The cross-sectional shape of the transmission pipe 30 and the whole transmission pipeline groove are specially designed, so that the L valve rod is prevented from rotating and moving in the channel transmission process, and the L valve rod is prevented from being blocked.

The L-valve stem 9, after sequencing and orientation of the hoppers, enters the right channel 3-2 of the right hopper 1-2 first. When the L valve rod passes through the right channel 3-2 of the right hopper 1-2, the counting sensor 5 detects and counts the direction of the L valve rod 9.

After the counting sensor 5 counts the number of the set workpieces, the left air cylinder pushes the left moving channel 41 on the left to move right, so that the discharge port of the left moving channel 41 is aligned with the feed port of the connecting valve rod fixing piece counting channel 6, the L valve rods sequentially enter the connecting valve rod fixing piece counting channel 6, and the L valve rods 9 are counted and sent to the workbench; then, the cylinder of the left moving channel 41 drives the left moving channel 41 to return, and the execution action of the left cylinder is limited by the left positioning device. The right cylinder performs the corresponding action.

The L valve rod is conveyed to the workbench in a well-ordered manner by repeating the steps. If the power failure occurs or the movement of the air cylinder is blocked in the working process, the air cylinder is automatically reset to the positioning device, and after the reset is completed and the check is correct, the power supply is recovered. Meanwhile, the main controller can be set to be recounted or continue to count.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are intended to further illustrate the principles of the invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention, which is also intended to be covered by the appended claims. The scope of the invention is defined by the claims and their equivalents.

Claims

1. A directional transmission method suitable for an L valve rod is characterized in that: comprises a hopper (1) and a hopper driving module (2); a trough (10) spirally rising along the inner wall of the hopper (1) is arranged in the hopper (1), and the outlet end of the trough (10) is connected with a valve rod transmission mechanism (3);

the hopper driving module (2) comprises an armature block (21) and a base (22) which are arranged below the hopper (1); the base (22) is connected with the armature block (21) through a plate spring (23); an inclination angle is arranged between the plate spring (23) and the base (22); a traction device (24) for driving the armature block (21) to descend is arranged on the base (22);

the hopper (1) comprises a left hopper (1-1) and a right hopper (1-2); the valve rod transmission mechanism (3) comprises a left channel (3-1) butted with the left hopper (1-1) and a right channel (3-2) butted with the right hopper (1-2); counting sensors (5) are arranged at the outlets of the left channel (3-1) and the right channel (3-2);

a discharge hole of the left channel (3-1) is provided with a left moving channel (41); a discharge port of the right channel (3-2) is provided with a right moving channel (42); the left moving channel (41) and the right moving channel (42) can butt the discharge port of the moving channel to the feeding port of the valve rod fixing piece counting channel (6) under the action of a pneumatic device;

the valve rod transmission mechanism (3) comprises a transmission pipe (30), and the section groove width B of the transmission pipe (30) is L + e;

according to the limiting conditions:

the allowable peak gap is obtained:

mu-sliding friction coefficient between the workpiece and the side wall, wherein B-transmission tube section groove width; l is the workpiece length of the valve rod; D-L workpiece width of the valve rod; e, a gap between the end face of the L valve rod and the inner wall of the transmission pipe; a horizontal included angle θ; a friction angle ρ; theta is the included angle between the diagonal C of the workpiece and the horizontal plane of the inner wall of the transmission pipe; rho is the included angle between the reaction force N of the inner wall of the transmission pipe and the horizontal plane of the inner wall of the transmission pipe when the valve rod rotates obliquely and touches the inner wall of the transmission pipe in the rolling process.

2. The directional transfer method for the L-stem according to claim 1, wherein: the traction device (24) is an electromagnet, and the traction device (24) is introduced with half-wave rectified pulsating voltage;

in 1/4 period from zero to peak current, the attraction force of the pulling device (24) is gradually increased, the armature block (21) drives the hopper (1) to move downwards, and the plate spring (23) is subjected to bending deformation;

when the current is in the period from the peak value to zero, the armature block (21) is driven to rotate upwards under the action of the plate spring (23).

3. The directional transfer method for the L-stem according to claim 1, wherein: the traction device (24) is a cylinder or an oil cylinder.