CN210312289U

CN210312289U - Sieve formula screw feeder that leaks

Info

Publication number: CN210312289U
Application number: CN201920886344.5U
Authority: CN
Inventors: 邓毅
Original assignee: Suzhou Pt Automation Technology Co ltd
Current assignee: Changzhou Platinum Electric Robot Co ltd
Priority date: 2019-06-13
Filing date: 2019-06-13
Publication date: 2020-04-14
Anticipated expiration: 2029-06-13

Abstract

The utility model discloses a sieve hourglass formula screw feeder, including the lid that shell and matching lid closed, the drive unit has been assembled from bottom to top in proper order in this shell of its characteristic, the ejector pin, the containing tray of infundibulate and the unit of leveling, wherein the containing tray bottom is equipped with the small opening, the containing tray is filled with screw and uncovered just to the stirring unit, ejector pin and the coaxial setting of small opening, the ejector pin tip is equipped with the blanking hole, the blanking hole of ejector pin wears to locate containing tray and one of them fixed setting up, the axial relative displacement under drive unit's guide arm transmission of containing tray or ejector pin of relative unfixed, and under the relative low-order state of ejector pin, the screw that the unit of leveling acted on in the containing tray under drive unit's instruction drive is fallen and is located. The feeder of the utility model has simple structure, realizes the separation of the screws one by one and keeps the positioning precision of the axial direction and the radial direction of the feeding; the screw feeding efficiency is improved while the manual operation is liberated and the safety is ensured, and the popularization and the application of various industrial assembly production lines are facilitated.

Description

Sieve formula screw feeder that leaks

Technical Field

The utility model relates to an assembly automation equipment especially relates to a be applied to screw continuous feeder of assembly line.

Background

With the improvement of the industrial production level and the scientific and technical level, the automation and intelligence degree of the production line is also changed day by day, and in the production process, screw assembly is a process with a long history and widely exists on various finished devices and equipment, and the quantity of the screw assembly is considerable.

For the automation line and the industrial robot that adapt to productivity efficiency and promote by a wide margin, this efficiency can't be satisfied in the tradition to rely on manpower and simple and crude appurtenance to carry out the feed, and the screw that stacks in a jumble moreover needs neatly arranged when the feed, and the finger is easily stabbed to the screw tip, and manpower intensity of labour is big and easily tired. While the technology is improved, various automatic feeding devices aiming at the screws are also provided in the market, but most of the automatic feeding devices are complex in structure and high in operation energy consumption. As mentioned above, the screws stacked in a mess usually need to be arranged in a relatively complicated arrangement process by a vibration plate and a screw guide rack after being poured into the automatic feeding device, so that the screws can be arranged in order and can be used for automatic assembly in a subsequent process. The vibration disc, the screw guide frame and the like are large in size, occupy limited space of a production line and energy consumption, and do not meet the requirements of energy conservation and emission reduction on large-scale production.

Therefore, the requirement of automatic high-precision feeding of screws is urgent, and according to different applications of assembly products, a plurality of screws are required at a time to meet the production efficiency so as to meet the market requirement.

Disclosure of Invention

In view of the not enough of above-mentioned prior art, the utility model aims at providing a sieve leaks formula screw feeder to satisfy the demand that scale assembly production line promoted screw feed precision and efficiency.

The utility model discloses a technical solution who realizes above-mentioned purpose is, a sieve hourglass formula screw feeder, including the lid that shell and matching lid closed, its characterized in that: a driving unit, a mandril, a funnel-shaped material containing tray and a sweeping unit are sequentially arranged in the shell from bottom to top, wherein the ejector rod and the material containing disc are coaxially arranged in pairs, the end part of the ejector rod is provided with a blanking hole, the inner diameter of the blanking hole is matched with the outer diameter of a single screw rod section to be fed and is smaller than the diameter of the screw cap end, the axial bottom end of the material containing disc is provided with a leakage hole, the material containing disc is filled with a screw and is just opposite to the sweeping unit, the blanking hole of the ejector rod upwards penetrates through the material containing disc, one of the ejector rod and the material containing disc is fixedly arranged, the relatively non-fixed material containing disc or the ejector rod axially and relatively displaces under the transmission of a guide rod of the driving unit, the displacement stroke range is between the condition that the blanking hole is flush with the leakage hole or lower than the condition that the leakage hole and the blanking hole exceed the end surface of the opening, and when the ejector rod is positioned at the lower limit of the stroke, the sweeping unit is driven by the instruction of the driving unit to act on the screw falling position in the material containing tray.

Furthermore, more than two pairs of material containing discs and ejector rods are arranged in the shell, and each pair of material containing discs and ejector rods are driven by a guide rod of the driving unit to synchronously and axially displace or asynchronously and axially displace.

Furthermore, six pairs of material containing trays and ejector rods are arranged in the shell, and each pair of material containing trays and ejector rods are arranged in a regular hexagon or uniform equi-circle distribution.

Furthermore, two to ten pairs of material containing trays and ejector rods are arranged in the shell, and each pair of material containing trays and ejector rods are distributed in a linear or array shape.

Furthermore, one of the material containing tray and the ejector rod is fixedly arranged, and the material containing tray or the ejector rod which is not fixed is controlled to axially displace.

Furthermore, the cover body is connected to the top of the feeder, and the cover body is provided with a through hole communicated with the alignment ejector rod outwards.

Furthermore, the lid connects and locates a lateral wall of a side of feeder, and the roof of shell is equipped with the thru hole that the counterpoint ejector pin outwards communicates.

Furthermore, the feeder is integrally provided with a sensor for detecting the screw excess material on the material containing disc, a screw storage bin connected with the sensor signal is arranged in the shell or outside the shell in a linked mode, and the screw storage bin is provided with a material supplementing channel facing the material containing disc.

Furthermore, the sensor is a gravity sensor for detecting the total weight of the screws in the material containing tray, or a grating sensor which is arranged on the side wall of the material containing tray close to the leakage hole and horizontally faces to the side wall on the opposite side.

The utility model discloses another technical solution who realizes above-mentioned purpose is, a sieve hourglass formula screw feeder, including the lid that shell and matching lid closed, its characterized in that: the shell is internally and sequentially provided with a driving unit, a mandril, a material containing tray and a sweeping unit from bottom to top, wherein the material containing tray is of a flat-bottom bowl-shaped structure, the area of the flat bottom is less than half of the area of the material containing tray, more than two leakage holes are distributed on the flat bottom, the material containing tray is filled with screws, and the opening of the material containing tray is opposite to the sweeping unit; the ejector rods correspond to the leakage holes in quantity and are coaxially arranged, blanking holes are formed in the end portions of the ejector rods, the inner diameters of the blanking holes are matched with the outer diameters of the single screw rod sections to be fed and are smaller than the diameters of the screw cap ends, and the blanking holes of the ejector rods penetrate through the material containing disc upwards; the ejector rod and one of the material containing discs are fixedly arranged, the material containing discs which are relatively non-fixed or the ejector rod axially and relatively displace under the transmission of a guide rod of the driving unit, the displacement stroke range is between the level of the blanking hole and the leakage hole or is lower than the level of the leakage hole and the level of the blanking hole and exceeds the open end face, the ejector rod is positioned in the stroke lower limit state, and the sweeping unit acts on the screws in the material containing discs to fall in all the blanking holes under the instruction driving of the driving unit.

Use the utility model discloses this technical solution of continuous feed possesses substantive characteristics and progressive, specifically speaking: the screw feeding device is simple in structure, and reliably realizes separation of screws in different directions one by one through axial relative movement, and completes the radial accurate positioning of the screws in the axial direction and the horizontal direction of the screws in the vertical direction, so that the screws can be accurately taken; the screw feeding efficiency is improved while the manual operation is liberated and the safety is ensured, and the popularization and the application of various industrial assembly production lines are facilitated.

Drawings

Fig. 1 is a process state diagram of the screw continuous feeding method of the present invention.

Fig. 2 is a schematic perspective view of a preferred embodiment of the sieve feeder of the present invention.

Fig. 3 is a schematic cross-sectional structure of fig. 2.

Fig. 4 is an enlarged schematic view of the screw to be fed.

Detailed Description

The following detailed description is made of specific embodiments of the present invention with reference to the accompanying drawings, so as to make the technical solution of the present invention easier to understand and grasp, and thus make a clearer definition of the protection scope of the present invention.

The utility model discloses the designer is to the artifical feed of prior art screw and have had automatic feed equipment many-sided not enough to carry out the integrated analysis under the practical application scene, combines self experience and creative work, and it is stable, reliable, safe to satisfy the screw high accuracy feed of modern industrial assembly line, and equipment cost optimization, energy saving and emission reduction's demand, and the innovation has provided a sieve hourglass formula screw feeder.

To more intuitively understand the innovative features of the sieve feeder of the present invention, please see the state of the screw feeding process shown in figure 1. The feeder is mainly realized by adopting a funnel-shaped material containing disc 1 and an ejector rod 2.

As can be seen in the figure, the material containing tray 1 is similar to a traditional funnel, although the shape structure is suitable for the integral assembly of the device and can be in various shapes, the upper surface is downwards concave to form a funnel tray structure in an inverted cone shape or a bowl shape, and the axial center is provided with a leakage hole 11. The inner diameter specification of the leak hole is matched with the ejector rod, and when the ejector rod is connected in the leak hole in a penetrating mode, a gap between the ejector rod and the leak hole is far smaller than the outer diameter of a rod section of the screw. The ejector rod 2 is a linear solid rod, and the bottom end of the ejector rod can be connected with a base for fixation and can also be connected with a driving device for axial transmission of acting force; the top end of the ram is provided with a blanking hole 21 compatible with the single screw 3 to be fed, as shown in close-up in the enlarged schematic view of fig. 4, the screw 3 having two parts, a stem section 31 and a cap end 32, which are integrally formed. The inner diameter of the blanking hole matches the outer diameter of the screw rod section 31 and is smaller than the outer diameter of the screw cap end 32, and the depth of the blanking hole also meets the condition that the rod section is completely immersed into the blanking hole. In addition to the illustrated embodiment, the top rod may also be a hollow rod, and the blanking hole is a section of the top of the cavity.

Although the blanking hole is matched with the external specification of the screw, the screw in the blanking hole can be positioned in the axial direction of the screw in the vertical direction and in the radial direction of the screw in the horizontal direction. However, in order to enable the screw to be easy to fall, a fine gap objectively exists between the blanking hole and the fallen screw, therefore, in order to improve the positioning accuracy and stability of the fallen screw, the ejector rod can be selectively designed to be provided with an externally connected negative pressure unit or a pneumatic clamp on the inner wall of the blanking hole, the negative pressure unit or the pneumatic clamp is controlled to be started after the screw falls and closed after the screw is taken, and the external force applied to the screw is smaller than half of the adsorption force of the screw head for taking the screw.

On the structure basis of the material containing disc and the ejector rod, the blanking hole of the ejector rod penetrates upwards from the leakage hole at the bottommost end of the material containing disc, then screws facing to different and disordered directions are stacked in the material containing disc, the material containing disc and the ejector rod carry out periodic axial displacement in the stroke range that the blanking hole 21 is flush with the leakage hole 11 and the blanking hole exceeds the open end face 12, and the ejector rod bears the screws in the blanking hole and is ready for taking materials. In the illustrated embodiment, the ejector rod 2 is fixed on the base and is fixedly arranged, so that the material containing disc moves axially and relatively, the material containing disc is lifted to keep two parallel holes within the stroke range, so that screws can be easily inserted and positioned in the material dropping holes, and when the material dropping is completed, the material containing disc slowly descends, so that the screws borne by the material dropping holes are separated upwards relative to the material containing disc and the rest of the screws, and the direction suitable for the cutter head of the screwdriver tool to take materials is kept. Of course, the relative movement of the material containing tray and the ejector rod can also exchange roles, namely, the material containing tray is fixedly arranged, and the ejector rod is used for generating the relative movement of axial displacement.

To understand more specifically, the relative movement process of fig. 1, which can be regarded as a cycle in the above-mentioned travel range, mainly includes three state stations of screw placement, exclusive straight-feeding and ejection. More specifically, in the state that the screws are located (shown in a left side I of fig. 1), the blanking hole 21 is flush with the leakage hole 11, the screws in the material containing disc are stacked in a disorderly manner, one of the screws to be fed can automatically drill into the blanking hole when the ejector rod 2 and the material containing disc 1 move oppositely, and the blanking is completed through inserting and positioning; the screw is slightly static, and the condition of abnormal position falling can occur in the relative movement process of the material containing tray and the ejector rod, at the moment, an action can be supplemented, namely, a moving part which is inserted into the material containing tray sweeps the material falling hole to enable the screw to be in a flowing state, and the specific form and the action mode of the moving part are detailed later. One of the flowing screws to be fed can automatically drill into the blanking hole at the moment when the rod section of the screw passes through the blanking hole, so that blanking is ensured to be finished.

Under the state station (shown in the right side II of the figure 1) of exclusive direct feeding, due to the relative movement of the material containing disc and the ejector rod, the blanking hole is fully occupied and sealed by one fallen screw, the blanking hole 21 penetrates upwards out of the leakage hole 11, no additional screw can be inserted and positioned in the blanking hole in the ascending process, the orientation of the fallen screw is unchanged, and therefore the ejector rod carries one fallen screw to ascend and pushes the rest screws outwards.

And under the ejection state (shown in the right side III of the figure 1), until the ascending process reaches the end point of the travel range, namely the blanking hole 21 of the ejector rod exceeds the open end surface 12 of the material containing disc, the screw cap end axially positioned in the blanking hole is upward and is opposite to the straight surface of the cutter head of the external screw cutter tool. And after the cutter head takes the materials, the blanking hole exposed in the idle state is set as a switching point of a feeding period (shown as IV on the left side of the figure 1).

Therefore, on the premise that the screws in the material containing disc can be supplemented in time, the ejector rod and the material containing disc move periodically relative to each other, the screws in the material containing disc can be accurately positioned and reliably prepared for material taking, the moving process is simple, and the feeding speed can be flexibly adjusted under the guarantee of certain efficiency.

From the perspective of access to an industrial assembly line, the above-described screen-through feed requires a relatively independent feeder, and allows the screw cap end ejected by the feed to be opposite to the bit of the screwdriver tool carried by the robotic arm of the production line. Generally, the cutter head and the screw are sucked from top to bottom, so that the sieve-type feeding scheme designed by the creation is easier to accurately butt joint and apply.

Fig. 2 and 3 are schematic perspective views and internal sectional views of a preferred embodiment of the sieve feeder of the present invention. As can be seen from the figures, the screen feeder, as a separate component of an auxiliary function on the production line, comprising the housing 4 and the cover 5 matching the cover, is the necessary infrastructure to facilitate modular exchange for maintenance of the equipment. From the more detailed structural characteristics, the shell 1 is internally provided with a driving unit 6, a mandril 2, a funnel-shaped material containing tray 1 and a sweeping unit 7 from bottom to top in sequence. Wherein ejector pin 2 and containing tray 1 coaxial setting in pairs, in order to improve the feeding efficiency, this embodiment has designed six pairs of ejector pins and containing tray and is the device of regular hexagon or the synchronous feed of circular distribution. From the structure of any pair of ejector pins and material containing discs, the end part of the ejector pin 2 is provided with a blanking hole 21 which is concave in the axial direction, and the inner diameter of the blanking hole 21 is matched with the outer diameter of a single screw rod section to be fed and is smaller than the diameter of a screw cap end, so that only a single screw can be ensured to be positioned in the blanking hole and the feeding is prepared properly. The axial bottom end of the material containing disc 1 is provided with a leakage hole 11, the material containing disc is filled with screws, the opening of the material containing disc is opposite to the sweeping unit 7, and the material falling hole of the ejector rod penetrates through the material containing disc upwards. The material containing disc and the ejector rod axially and relatively displace under the transmission of a guide rod of the driving unit, the displacement range is between the parallel and level of the blanking hole and the leakage hole and the position of the blanking hole beyond the open end face, and the sweeping unit is driven by the instruction of the driving unit to act on the screw falling position in the material containing disc under the parallel and level state of the blanking hole and the leakage hole.

In addition, the sweeping unit is the moving part and can be a brush or a flexible sheet which axially rotates or horizontally slides, the force is applied to the screw which sweeps the abnormal position on the surface of the blanking hole, and the disordered screw is in a flowing state. The cover body 5 is provided with a through hole 51 communicating with the aligning mandril to facilitate the tool bit of the screwdriver tool to be inserted into the feeder and suck the screw.

In the feeding process of the components, the ejector rod and the material containing disc are driven to move relatively, so that the blanking hole moves up and down relatively along the leakage hole. The screw that waits to feed among the holding tray of holding tray under the normal condition stacks and has the take the material back vacated by the tool bit under, relative small opening decline in-process holding tray screw can seek the small opening automatically and accomplish the position that falls, and when small opening and small opening parallel and level or small opening in the small opening, the small opening is sheltered from by mixed and disorderly screw and still normally falls the position, then sweep the unit action and exert the disturbance power towards the screw in the holding tray, sweep the vacation small opening on the one hand, on the other hand makes the screw be mobile form, make like this the screw can find the small opening and peg graft the location wherein. After the screw blanking is finished, the driving unit drives the material containing disc to move downwards or the ejector rod to jack upwards, and the residual screws in the radial direction of the ejector rod in the process are discharged. Until the ejector rod rises to reach the stroke end point, a single screw with the upward cap end and stable seating and positioning is exposed, and feeding in one period is completed. Meanwhile, when the blanking hole is empty, the ejector rod retracts to prepare for feeding in the next period.

It can be easily found that in the single-period feeding process, the movement change amplitude of the ejector rod and the sweeping unit is small, and the direction is single. The screen feeder therefore provides increased feed rate and accuracy for efficient industrial assembly applications.

In addition, it can be seen that the feeder is further provided with a screw storage bin 8 in the housing, and the screw storage bin 8 is provided with a screw feeding channel (not shown) facing the material containing tray 1. When the screws in the material containing tray gradually decrease along with the periodic feeding, the screws can be supplemented in time. Under the condition, the gravity sensor can be additionally arranged at the bottom of the material containing disc, and when the screws in the material containing disc are smaller than a preset total weight threshold value, automatic material supplementing can be driven. Of course, the screw discharge bin may also be externally coupled into the housing of the feeder.

In addition to the above preferred embodiments, the number and distribution of the pairs of the ejector pins and the material containing trays in the sieve feeder may be varied, and the sieve feeder is not limited to the above embodiments and the drawings. For example, a single pair may be provided as the feeder, or three or more pairs may be linearly arranged as the feeder assembly. Furthermore, for a plurality of pairs of feeders, each pair of feeder units may be fed synchronously as in the preferred embodiment, or may be fed asynchronously or alternately periodically and controlled to be driven individually.

As another expanded embodiment, the material containing tray can be in a flat-bottom bowl shape, the area of the flat bottom is less than half of the area of the material containing tray, more than two leakage holes are distributed on the flat bottom, screws are filled in the material containing tray, and the opening of the material containing tray is opposite to the sweeping unit; the ejector rods correspond to the number of the leakage holes and are coaxially arranged, and the end parts of the ejector rods are provided with blanking holes which are concave in the axial direction or directly hollow rods; the ejector rod and one of the material containing discs are fixedly arranged, the material containing discs which are relatively non-fixed or the ejector rods axially and relatively displace under the transmission of a guide rod of the driving unit, the displacement stroke range is between the level of the blanking hole and the leakage hole and the level of the blanking hole exceeding the open end face, and the sweeping unit is driven by the instruction of the driving unit to act on the screws in the material containing discs to fall in the blanking holes of all the ejector rods under the condition that the blanking hole and the leakage hole are level or slightly lower than the leakage hole. Synchronous feeding is taken as a representative implementation explanation, after all the ejector rods finish the screw falling, all the ejector rods are synchronously driven and jacked by the driving unit, and therefore batch feeding is achieved. Of course, the rams may also be driven partially synchronously and partially asynchronously.

To sum up, the sieve-type screw feeder of the present invention is described in detail in conjunction with the illustrated embodiments, and it will be understood that it has substantial features and improvements: the device for realizing the continuous feeding of the screws has a simple structure, reliably realizes the separation of the screws in a pile facing different directions one by one through the axial relative motion, and completes the radial accurate positioning of the screws in the axial direction and the horizontal direction of the screws in the vertical direction, so that the screws can be accurately taken; the screw feeding efficiency is improved while the manual operation is liberated and the safety is ensured, and the popularization and the application of various industrial assembly production lines are facilitated.

The preferred embodiments of the present invention have been described in detail, but the technical innovation of the present invention is not limited to the above specific embodiments. The scope of the invention is to be construed as limited only by the appended claims.

Claims

1. The utility model provides a sieve hourglass formula screw feeder, includes the lid that shell and matching lid closed, its characterized in that: a driving unit, a mandril, a funnel-shaped material containing tray and a sweeping unit are sequentially arranged in the shell from bottom to top, wherein the ejector rod and the material containing disc are coaxially arranged in pairs, the end part of the ejector rod is provided with a blanking hole, the inner diameter of the blanking hole is matched with the outer diameter of a single screw rod section to be fed and is smaller than the diameter of the screw cap end, the axial bottom end of the material containing disc is provided with a leakage hole, the material containing disc is filled with a screw and is just opposite to the sweeping unit, the blanking hole of the ejector rod upwards penetrates through the material containing disc, one of the ejector rod and the material containing disc is fixedly arranged, the relatively non-fixed material containing disc or the ejector rod axially and relatively displaces under the transmission of a guide rod of the driving unit, the displacement stroke range is between the condition that the blanking hole is flush with the leakage hole or lower than the condition that the leakage hole and the blanking hole exceed the end surface of the opening, and when the ejector rod is positioned at the lower limit of the stroke, the sweeping unit is driven by the instruction of the driving unit to act on the screw falling position in the material containing tray.

2. The screen-type screw feeder of claim 1, wherein: more than two pairs of material containing discs and ejector rods are arranged in the shell, and each pair of material containing discs and ejector rods are driven by a guide rod of the driving unit to synchronously and axially displace or asynchronously and axially displace.

3. The screen-type screw feeder of claim 2, wherein: six pairs of material containing discs and ejector rods are arranged in the shell, and each pair of material containing discs and ejector rods are arranged in a regular hexagon or uniform equi-circle distribution.

4. The screen-type screw feeder of claim 2, wherein: two to ten pairs of material containing discs and ejector rods are arranged in the shell, and each pair of material containing discs and ejector rods are distributed linearly or in an array.

5. The sift screw feeder of any one of claims 1 to 4, wherein: one of the material containing tray and the ejector rod is fixedly arranged, and the material containing tray or the ejector rod which is relatively non-fixed is controlled to axially displace.

6. The screen-type screw feeder of claim 1, wherein: the cover body is connected to the top of the feeder and provided with a through hole communicated with the alignment ejector rod outwards.

7. The screen-type screw feeder of claim 1, wherein: the lid connects and locates a lateral wall on one side of feeder, and the roof of shell is equipped with the thru hole that the counterpoint ejector pin communicates outward.

8. The screen-type screw feeder of claim 1, wherein: the feeder is characterized in that a sensor for detecting the excess material of the screw is integrally arranged on the material containing disc, a screw storage bin connected with a signal of the sensor is arranged in the shell or outside the shell of the feeder in a linked mode, and a material supplementing channel is arranged on the screw storage bin facing the material containing disc.

9. The screen-type screw feeder of claim 8, wherein: the sensor is a gravity sensor for detecting the total weight of the screws in the material containing disc or a grating sensor which is arranged on the side wall of the material containing disc close to the leakage hole and horizontally faces to the side wall on the opposite side.

10. The utility model provides a sieve hourglass formula screw feeder, includes the lid that shell and matching lid closed, its characterized in that: the shell is internally and sequentially provided with a driving unit, a mandril, a material containing tray and a sweeping unit from bottom to top, wherein the material containing tray is of a flat-bottom bowl-shaped structure, the area of the flat bottom is less than half of the area of the material containing tray, more than two leakage holes are distributed on the flat bottom, the material containing tray is filled with screws, and the opening of the material containing tray is opposite to the sweeping unit; the ejector rods correspond to the leakage holes in quantity and are coaxially arranged, blanking holes are formed in the end portions of the ejector rods, the inner diameters of the blanking holes are matched with the outer diameters of the single screw rod sections to be fed and are smaller than the diameters of the screw cap ends, and the blanking holes of the ejector rods penetrate through the material containing disc upwards; the ejector rod and one of the material containing discs are fixedly arranged, the material containing discs which are relatively non-fixed or the ejector rod axially and relatively displace under the transmission of a guide rod of the driving unit, the displacement stroke range is between the level of the blanking hole and the leakage hole or is lower than the level of the leakage hole and the level of the blanking hole and exceeds the open end face, the ejector rod is positioned in the stroke lower limit state, and the sweeping unit acts on the screws in the material containing discs to fall in all the blanking holes under the instruction driving of the driving unit.