CN212709500U

CN212709500U - Infrared turnover vehicle for goods shelf

Info

Publication number: CN212709500U
Application number: CN202020970319.8U
Authority: CN
Inventors: 王华军
Original assignee: Huangyu Intelligent Logistics Equipment Nanjing Co ltd
Current assignee: Huangyu Intelligent Logistics Equipment Nanjing Co ltd
Priority date: 2020-06-01
Filing date: 2020-06-01
Publication date: 2021-03-16
Anticipated expiration: 2030-06-01

Abstract

An infrared turnover vehicle for a goods shelf comprises a turnover vehicle, wherein the bottom of the turnover vehicle is provided with a bottom frame of universal wheels, and a plurality of goods shelf units for placing goods are arranged on the bottom frame along the vertical direction; one end of the bottom frame is also connected with one end of the hand push frame; the infrared sensor is arranged in the middle of the end wall of the other end of the bottom frame and connected with the controller, the controller is connected with the signal relay, the signal relay is provided with a normally open contact, and the normally open contact is connected between the power supply of the buzzer and the power supply of the buzzer in series. The goods placed on the goods shelf unit in the prior art are effectively prevented from blocking the sight of an operator by combining with other structures, so that the danger that the turnover vehicle collides with the pedestrian frequently occurs if the pedestrian appears in front of the turnover vehicle, the turnover vehicle is unsafe when transporting the goods shelf unit, the radian of the hand push frame cannot be changed, the use is inconvenient, and particularly the defects that the use is inconvenient for operators with different heights are overcome.

Description

Infrared turnover vehicle for goods shelf

Technical Field

The utility model belongs to the technical field of the goods shelves transportation, also belong to infrared technical field, concretely relates to infrared turnover vehicle for goods shelves.

Background

The turnover vehicle is a necessary tool in life and production, and in life, hand-push shopping carts in supermarkets, shopping carts in airports, and the like can be seen everywhere for people to save energy. The turnover vehicle is a tool for carrying goods, generally comprises a goods shelf, universal wheels are mounted at the bottom of the goods shelf, the goods are loaded on the goods shelf when being carried, and are driven to a destination in a hand-pushing mode, and the goods are unloaded after reaching the destination. In order to ensure that the capacity of the current turnover vehicle is large enough, a plurality of layers of goods trays for placing goods are arranged on a goods shelf.

The bottom of the turnover vehicle is provided with an underframe with universal wheels, a plurality of goods shelf units for placing goods are arranged on the underframe in the vertical direction, one end of the underframe is connected with one end of a hand push frame in a bolt screwing mode, so that an operator can push the hand push frame to move the universal wheels of the turnover vehicle, the hand push frame is driven to move the goods shelf units for placing the goods on the underframe together, and the goods turnover vehicle plays a role. However, when the operator pushes the turnover vehicle, the goods placed on the shelf units often block the sight of the operator, so that if a pedestrian appears in front of the turnover vehicle, the danger that the turnover vehicle collides with the pedestrian often occurs, and the defect that the turnover vehicle is unsafe when transporting the shelf units is caused.

In addition, the hand-push frame is generally of an integral structure, the radian of the hand-push frame cannot be changed, and the hand-push frame has the defect of inconvenient application, and is particularly inconvenient for operators with different heights.

Disclosure of Invention

In order to solve the problem, the utility model provides an infrared turnover vehicle for goods shelves, the goods that have effectively avoided among the prior art goods shelves unit to place shelters from operator's sight makes and takes place the danger that turnover vehicle and pedestrian hit often if the pedestrian appears in the place ahead of turnover vehicle, takes place unsafe, the unable change of radian of hand push frame and make the application inconvenient, especially towards the defect of very inconvenient of the operator of different height when leading to turnover vehicle transportation goods shelves unit.

In order to overcome the deficiencies in the prior art, the utility model provides a solution that is used for infrared turnover vehicle of goods shelves specifically as follows:

an infrared turnover vehicle for a goods shelf comprises a turnover vehicle, wherein the bottom of the turnover vehicle is provided with a bottom frame of universal wheels, and a plurality of goods shelf units for placing goods are arranged on the bottom frame along the vertical direction;

one end of the bottom frame is also connected with one end of the hand push frame;

the infrared sensor is arranged in the middle of the end wall of the other end of the bottom frame and connected with the controller, the controller is connected with the signal relay, the signal relay is provided with a normally open contact, and the normally open contact is connected between the power supply of the buzzer and the power supply of the buzzer in series.

Furthermore, the model of the infrared sensor is an infrared 5V photoelectric switch K1 of E18-D80NK, and the controller is an 8051 singlechip;

and the signal output end of the infrared 5V photoelectric switch K1 of the E18-D80NK model is connected with a pin 39 of the 8051 singlechip.

Further, the signal relay is a 3.3V single-path relay of the general element micro intelligent technology limited company, and the buzzer is a 5V active buzzer K2 of BAYMAK model;

a pin 1 of the 8051 single-chip microcomputer is connected with one end of a coil of the 3.3V single-circuit relay T1, and the other end of the coil of the 3.3V single-circuit relay is grounded;

the power supply of the 5V active buzzer is a 5V lithium battery of 09AQ502-01 model, the anode of the 5V lithium battery is also connected with the power supply terminal of the infrared 5V photoelectric switch K1 of E18-D80NK model, namely, the 5V lithium battery also supplies power for the infrared 5V photoelectric switch K1 of E18-D80NK model, and the cathode of the 5V lithium battery is grounded.

Further, the positive pole Vcc5 of 5V lithium cell is connected with 1 foot of MIC5205-3.3 low dropout regulator, 2 feet of MIC5205-3.3 low dropout regulator are grounded, 5 feet of MIC5205-3.3 low dropout regulator are used for outputting 3.3V voltage, 5 feet of MIC5205-3.3 low dropout regulator, 40 feet of 8051 singlechip and 31 feet of 8051 singlechip are connected.

Further, the hand push frame comprises a columnar driving column 2 connected with one end of the bottom frame and a ring-shaped holding part 3 which can be screwed on the top of the driving column through a columnar roller 5; the drive column is provided at its top end with an inverted arch-shaped coupling portion 6 comprising a lower plate 62 connected to the top end of the drive column and a pair of side walls 63 juxtaposed to each other, the side walls and the drive column being juxtaposed to each other, and a manual setting variation device 4 for varying the rotational arc of the grip portion around the roller is provided between the drive column and the grip portion.

Furthermore, the manual embedding equipment comprises a disc-shaped embedding block 45 which is fixedly arranged on the roller and is vertical to the roller, a plurality of embedding openings 44 which are arranged on the circumferential edge of the disc-shaped embedding block and used for positioning, a manual pressing plate 42 which is arranged on the driving column and can move towards the direction of the circle center of the roller, and a columnar positioning column 46 which is arranged on the manual pressing plate and combined with the embedding openings used for positioning.

Furthermore, the rollers can be rotatably arranged on the pair of side walls, roller holes are formed in the pair of side walls, and the rollers penetrate through the roller holes; the roller is vertical to the driving column; the rollers are perpendicular to the side walls. The two ends of the roller of the utility model are respectively provided with the disc-shaped scarf joint blocks, and the other pair of side walls are positioned between the disc-shaped scarf joint blocks at the two ends of the roller.

Further, the central line of the disc-shaped scarfing block is consistent with the central line of the roller; the positioning columns are parallel to the rollers; a first rod-shaped guide opening 64 extending towards the center of the roller is arranged on the side wall, and the first rod-shaped guide opening extends towards the center of the roller in the same direction as the driving column; the manual pressure plate is positioned between a pair of side walls.

Furthermore, a second rod-shaped guide port 43 is arranged on the manual pressure plate, and the direction of the second rod-shaped guide port extending towards the center of the roller is parallel to the direction of the first rod-shaped guide port extending towards the center of the roller; the roller penetrates through the rod-shaped guide opening II; the positioning column penetrates through the rod-shaped guide opening I; a plate spring 47 in a pressing state is arranged between the manual pressing plate and the lower plate body.

Further, the holding part is fixedly connected with the disc-shaped embedding blocks, the disc-shaped embedding blocks at two ends of the roller are positioned between two ends of the holding part, and the head part of the holding part is in threaded connection with the corresponding disc-shaped embedding blocks through screws.

The utility model has the advantages that:

the utility model discloses when the operator hand push frame lets the turnover vehicle drive the goods shelves unit turnover motion of placing the goods, the mode that utilizes its infrared induction at infrared sensor detects its the place ahead, exactly it is when the place ahead of turnover vehicle has the people, the controller will turn on signal relay, let normally open contact closed, just so can switch on buzzer buzzing, remind operator the place ahead someone, with this operator just can stop to promote the hand push frame or let the hand push frame turn to avoid the pedestrian in turnover vehicle the place ahead, perhaps the pedestrian also can hear and in time avoid after the buzzer rings, the security is good, effectively avoided if the place ahead of turnover vehicle the pedestrian appear can take place the danger that turnover vehicle and pedestrian hit often, take place unsafe defect when leading to turnover vehicle transportation goods shelves unit. The hand-push frame of the utility model has the advantages of uncomplicated structure, convenient operation, low manufacturing cost and suitability for operators with different heights.

Drawings

Fig. 1 is a schematic connection diagram of the controller of the present invention.

Fig. 2 is a circuit diagram of the 8051 single chip microcomputer of the present invention.

Fig. 3 is a schematic connection diagram of the signal relay of the present invention.

Fig. 4 is a schematic connection diagram of the MIC5205-3.3 low dropout regulator of the present invention.

Fig. 5 is an overall schematic view of the hand push frame of the present invention.

Fig. 6 is a partial schematic view at Y of fig. 5.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples.

As shown in fig. 1-6, an infrared turnover vehicle for a shelf includes a turnover vehicle, a bottom frame of a universal wheel is disposed at the bottom of the turnover vehicle, a plurality of shelf units for placing goods are disposed on the bottom frame along a vertical direction, a vertical downward plug-in unit is disposed at the bottom of the shelf unit, a slot for the plug-in unit to be inserted is disposed at the top of the shelf unit, a plurality of elastic clamping members are disposed along a length direction of the plug-in unit, a plurality of clamping slots correspondingly clamped with the elastic clamping members one by one are disposed on the inner wall of the slot, a slot consistent with the slot at the top of the shelf is disposed on the bottom frame, and when the plug-in unit of one shelf unit is completely inserted into and matched with the slot of the shelf unit adjacent to the lower side, opposite contact surfaces of two adjacent shelf units are abutted; one end of the bottom frame is connected with one end of the hand push frame in a bolt connection mode; the infrared sensor is arranged in the middle of the end wall of the other end of the bottom frame and connected with the controller, the controller is connected with the signal relay, the signal relay is provided with a normally open contact, and the normally open contact is connected between the power supply of the buzzer and the power supply of the buzzer in series. Therefore, when the infrared sensor detects the front of the turnover vehicle in an infrared sensing mode, namely when people are in the front of the turnover vehicle, the controller can conduct the signal relay to close the normally open contact, so that the buzzer can be communicated for buzzing, people are reminded of the front of an operator, the operator can stop pushing the hand push frame or steering the hand push frame to avoid pedestrians in the front of the turnover vehicle, or the pedestrians can also hear the buzzer and then avoid the pedestrians in the front of the turnover vehicle in time, the safety is good, and the defect that the danger that the turnover vehicle collides with the pedestrians when the pedestrians appear in the front of the turnover vehicle and the defect that the turnover vehicle is unsafe when a goods shelf unit is transported is overcome is effectively avoided. The power supplies of the signal relay, the buzzer and the buzzer are fixedly connected to the bottom of the bottom frame in an adhesive tape binding mode or a screw connection mode. The model of the infrared sensor is an infrared 5V photoelectric switch K1 of E18-D80NK, and the controller is an 8051 single chip microcomputer; and the signal output end of the infrared 5V photoelectric switch K1 of the E18-D80NK model is connected with a pin 39 of the 8051 singlechip. The infrared detection range of the E18-D80NK type infrared 5V photoelectric switch K1 is within 0.8m, so when a pedestrian within the range of 0.8m is detected by the E18-D80NK type infrared 5V photoelectric switch K1, the related sensed infrared signals are transmitted to the 8051 single chip microcomputer to conduct corresponding connection processing on a signal relay. The signal relay is a 3.3V single-path relay of a Tongyuan micro intelligent technology limited company, and the buzzer is a 5V active buzzer K2 of a BAYMAK model; a pin 1 of the 8051 single-chip microcomputer is connected with one end of a coil of the 3.3V single-circuit relay T1, and the other end of the coil of the 3.3V single-circuit relay is grounded; the power supply of the 5V active buzzer is a 5V lithium battery of 09AQ502-01 model, the anode of the 5V lithium battery is also connected with the power supply terminal of the infrared 5V photoelectric switch K1 of E18-D80NK model, namely, the 5V lithium battery also supplies power for the infrared 5V photoelectric switch K1 of E18-D80NK model, and the cathode of the 5V lithium battery is grounded. Therefore, after the 8051 single-chip microcomputer receives the sensed infrared signal, 1 pin of the 8051 single-chip microcomputer outputs a high level, so that a coil of the 3.3V single-path relay can be electrified, a normally open contact of the relay is closed, a 5V active buzzer of a BAYMAK model rings, an operator is reminded of someone in front of the operator, the operator can stop pushing the hand push frame or turn the hand push frame to avoid a pedestrian in front of the turnover vehicle, or the pedestrian can hear the buzzer and then avoid the buzzer in time, the safety is good, and the defect that the danger that the turnover vehicle collides with the pedestrian often happens and the safety is caused when the turnover vehicle transports the goods shelf unit if the pedestrian appears in front of the turnover vehicle is effectively overcome.

The positive pole Vcc5 of 5V lithium cell is connected with 1 foot of MIC5205-3.3 low dropout regulator, 2 feet of MIC5205-3.3 low dropout regulator are grounded, 5 feet of MIC5205-3.3 low dropout regulator are used for exporting the voltage of 3.3V, 5 feet of MIC5205-3.3 low dropout regulator, 40 feet of 8051 singlechip and 31 feet of 8051 singlechip are connected. The pin 5 of the MIC5205-3.3 low dropout regulator, the pin 40 of the 8051 singlechip are connected with the pin 31 of the 8051 singlechip, so that the 5V voltage of the 5V lithium battery is converted into 3.3V voltage to be supplied to the 8051 singlechip to achieve the purpose of supplying power to the 8051 singlechip.

Therefore, when the operator pushes the hand push frame to drive the turnover vehicle to drive the goods shelf unit for placing goods to turnover, the infrared sensor detects the front of the turnover vehicle in an infrared sensing mode, namely when the front of the turnover vehicle is occupied by a person, the controller can conduct the signal relay to close the normally open contact, so that the buzzer can be connected to conduct buzzing, the person in front of the operator is reminded, the operator can stop pushing the hand push frame or turn the hand push frame to avoid the pedestrian in front of the turnover vehicle, or the pedestrian can hear the buzzer to avoid the pedestrian in time after ringing, the safety is good, and the defect that the danger that the turnover vehicle and the pedestrian collide with each other often and the safety is caused when the turnover vehicle transports the goods shelf unit can be effectively overcome.

In addition, the turnover vehicle can enable an operator to push the hand push frame to enable the universal wheels of the turnover vehicle to move, so that the goods shelf units on the underframe for placing goods are driven to move together, and the goods turnover vehicle plays a role in goods turnover. When the turnover vehicle is used, the number of the needed goods shelf units is roughly judged according to the number of the goods, then the goods shelf units with the corresponding number are arranged on the chassis, when only part of the goods are left, the goods shelf units which are not used are disassembled, the quality of the turnover vehicle is effectively reduced, and therefore the phenomenon that redundant strength is consumed when fewer goods are carried is avoided. When installing the goods shelves unit, just inserting the plug-in components of goods shelves unit vertically to the slot on the chassis, the plug-in components move towards the tank bottom of slot along the slot always, elasticity joint spare carries out the joint with the joint groove in proper order, until plug-in components insert to the bottom of slot, plug-in components peg graft completely with the slot, elasticity joint spare and joint groove joint one by one this moment, the goods shelves unit is installed on the chassis, when needing to increase the goods shelves unit, install with same mode, the required capacity demand of a plurality of goods shelves unit of stack in order to satisfy the goods. The fixing of the plug-in and the slot is stable through a plurality of elastic clamping mechanisms on the plug-in, and the stable installation of the shelf unit is ensured. When the goods is less, avoid consuming unnecessary strength, dismantle the goods shelves unit that does not use down, draw the vertical orientation of the goods shelves unit of highest point hard in proper order and get, a plurality of elastic joint spare break away from the joint groove of self joint in proper order, and the goods shelves unit can be dismantled smoothly. Through the dismantled setting of goods shelves unit to make the turnover vehicle can in time adjust the quantity of goods shelves unit according to the quantity of goods, carry out dismouting goods shelves unit through the mode that plug-in components and slot were pegged graft, comparatively simple swift when making increase or reduce goods shelves unit, this turnover vehicle simple structure, goods shelves unit's easy dismounting, have higher practicality.

The hand push frame comprises a columnar driving column 2 connected with one end of the bottom frame and a ring-shaped holding part 3 which can be screwed on the top of the driving column through a columnar roller 5; the holding part is bent and rolled into a ring shape. The bottom of the driving column is connected with the bottom frame, and the top of the driving column extends upwards in an inclined mode. The drive column is provided at its top end with an inverted arch-shaped coupling portion 6 comprising a lower plate 62 connected to the top end of the drive column and a pair of side walls 63 juxtaposed to each other, the side walls and the drive column being juxtaposed to each other, and a manual setting variation device 4 for varying the rotational arc of the grip portion around the roller is provided between the drive column and the grip portion. The structure of the driving column 2 connected with one end of the underframe is as follows: one end of the driving column 2 is connected with one end of the underframe in a bolt screwing mode.

Thus, the radian of the holding part can be changed by rotating the holding part 3, so that the operation of operators with different heights is facilitated, and the operation is convenient; in addition, the structure is not complex, the operation is convenient, and the manufacturing cost is not high; in addition, the grip portion can be folded even when the cart is not in use, and the cart is convenient for storage.

The manual embedding and changing equipment comprises a disc-shaped embedding block 45 which is fixedly arranged on the roller and is vertical to the roller, a plurality of embedding openings 44 which are arranged on the periphery of the disc-shaped embedding block and used for positioning, a manual pressing plate 42 which is arranged on the driving column and can move towards the direction of the circle center of the roller, and a columnar positioning column 46 which is arranged on the manual pressing plate and combined with the embedding openings used for positioning. The number of the scarf joint openings for positioning is higher than one pair; the rollers can be rotatably arranged on the pair of side walls, in particular, roller holes are formed in the pair of side walls, and the rollers penetrate through the roller holes; the roller is vertical to the driving column; the rollers are perpendicular to the side walls. The two ends of the roller of the utility model are respectively provided with the disc-shaped scarf joint blocks, and the other pair of side walls are positioned between the disc-shaped scarf joint blocks at the two ends of the roller. Such a manual fitting variation device is advantageous for varying the curvature of the holding portion. The central line of the disc-shaped scarf block is consistent with the central line of the roller; the positioning columns are parallel to the rollers; a first rod-shaped guide opening 64 extending towards the center of the roller is arranged on the side wall, and the first rod-shaped guide opening extends towards the center of the roller in the same direction as the driving column; the manual pressure plate is positioned between a pair of side walls. The manual pressure plate is provided with a rod-shaped guide port II 43, and the direction of the rod-shaped guide port II extending towards the center of the roller is parallel to the direction of the rod-shaped guide port I extending towards the center of the roller; the roller penetrates through the rod-shaped guide opening II; the positioning column penetrates through the rod-shaped guide opening I; a plate spring 47 in a pressing state is arranged between the manual pressing plate and the lower plate body. The holding part is fixedly connected with the disc-shaped embedding block, the disc-shaped embedding block at the two ends of the roller is positioned between the two ends of the holding part, and the head part of the holding part is in threaded connection with the corresponding disc-shaped embedding block through a screw. Thus, the manual pressing plate is pressed downwards by hand, and the positioning column is drawn to move downwards, so that the positioning column is moved to the outside of the scarf joint opening for positioning; in this case, the operator can change the curvature of the grip portion by rotating the grip portion, that is, the grip portion rotates around the roller, and thus the operator can easily handle the grip portion with different heights. The disc-shaped embedding block can be pulled to rotate together during the rotation of the holding part, and after the rotating radian of the holding part is changed to the right position, an operator releases the manual pressing plate, and at the moment, the positioning column is connected to the peripheral edge of the disc-shaped embedding block under the elastic force of the plate spring in a pressing state; then, the operator rotates the holding part properly to make the other embedding port for positioning on the disc-shaped embedding block opposite to the positioning column, and when the embedding port for positioning is opposite to the positioning column, the positioning column is embedded into the embedding port for positioning under the elastic force of the plate spring in a pressing state, so that the position of the holding part is stabilized. When the turnover vehicle is not in use, the holding part can be rotated downwards to bend and fold, and the positioning column is inserted into the embedding opening for positioning.

Having thus described the present invention by way of example, it will be appreciated by those skilled in the art that the present disclosure is not limited to the embodiments described above, and that various changes, modifications and substitutions may be made without departing from the scope of the invention.

Claims

1. The infrared turnover vehicle for the goods shelf is characterized by comprising a turnover vehicle, wherein the bottom of the turnover vehicle is provided with a bottom frame of universal wheels, and a plurality of goods shelf units for placing goods are arranged on the bottom frame in the vertical direction;

2. The infrared turnover vehicle for racks as claimed in claim 1, wherein the model of the infrared sensor is model E18-D80NK infrared 5V photoelectric switch K1, and the controller is an 8051 single chip microcomputer;

3. The infrared turnover vehicle for racks of claim 2,

the signal relay is a 3.3V single-path relay of a Tongyuan micro intelligent technology limited company, and the buzzer is a 5V active buzzer K2 of a BAYMAK model;

4. The infrared turnover vehicle for the shelf as claimed in claim 3, wherein the positive electrode Vcc5 of the 5V lithium battery is connected with 1 pin of the MIC5205-3.3 low dropout regulator, 2 pins of the MIC5205-3.3 low dropout regulator are grounded, 5 pins of the MIC5205-3.3 low dropout regulator are used for outputting 3.3V voltage, and 5 pins of the MIC5205-3.3 low dropout regulator, 40 pins of the 8051 single chip microcomputer and 31 pins of the 8051 single chip microcomputer are connected.

5. The infrared turnover vehicle for racks of claim 1, wherein the hand push frame includes a cylindrical driving column connected to one end of the under frame and a ring-shaped grip portion rotatably attached to a top portion of the driving column via a cylindrical roller; the top end of the driving column is provided with an inverted arch-shaped connecting part, the inverted arch-shaped connecting part comprises a lower plate body connected with the top end of the driving column and a pair of side walls which are parallel to each other, in addition, the side walls are parallel to the driving column, and a manual embedding and changing device for changing the rotating radian of the holding part around the roller is arranged between the driving column and the holding part.

6. The infrared turnover vehicle for racks of claim 5, wherein the manual embedding and changing device comprises a disk-shaped embedding block fixed on the roller and perpendicular to the roller, a plurality of embedding ports for positioning arranged on the peripheral edge of the disk-shaped embedding block, a manual pressing plate arranged on the driving column and capable of moving towards the center of the roller, and a column-shaped positioning column arranged on the manual pressing plate and combined with the embedding ports for positioning.

7. The infrared turnover vehicle for racks of claim 6, wherein said rollers are rotatably disposed on a pair of said side walls, a pair of said side walls being provided with roller holes, said rollers being penetrated through said roller holes; the roller is vertical to the driving column; the rollers are perpendicular to the side walls; the two ends of the roller are respectively provided with a disk-shaped scarf joint block, and the other pair of side walls are positioned between the disk-shaped scarf joint blocks at the two ends of the roller.

8. The infrared turnover vehicle for racks of claim 7, wherein a center line of the disk-shaped scarf block is coincident with a center line of the roller; the positioning columns are parallel to the rollers; the side wall is provided with a first rod-shaped guide opening extending towards the center of the roller, and the direction of the first rod-shaped guide opening extending towards the center of the roller is parallel to the driving column; the manual pressure plate is positioned between a pair of side walls.

9. The infrared turnover vehicle for the shelf as claimed in claim 8, wherein the second rod-shaped guide opening is provided on the manual pressure plate, and the direction of the second rod-shaped guide opening extending toward the center of the roller is parallel to the direction of the first rod-shaped guide opening extending toward the center of the roller; the roller penetrates through the rod-shaped guide opening II; the positioning column penetrates through the rod-shaped guide opening I; and a plate spring in a pressing state is arranged between the manual pressing plate and the lower plate body.

10. The infrared turnover vehicle for racks of claim 8, wherein the grip portion is fixedly connected to a disk-shaped engagement piece, the disk-shaped engagement piece at both ends of the roller is located between both ends of the grip portion, and the head portion of the grip portion and the corresponding disk-shaped engagement piece are screwed via a screw.