JP7574706B2 - Lifting device and moving body - Google Patents

Description

Applicable under Article 30, Paragraph 2 of the Patent Act. Sold to DENSO Hokkaido Co., Ltd. on December 21, 2020.

The present invention relates to a lifting device and a moving body.

Autonomous automated guided vehicles are often used as a means of transporting basket carts in factories, warehouses, etc. Previously, the mainstream method was to transport the basket cart while the travelling device was towing it, but in recent years, taking into consideration the turning radius and travel aisle width, transportation by low-floor automated guided vehicles that can crawl into the basket cart and transport has been increasing. There are two main methods of crawling into the basket cart and transporting: the crawling towing type, in which a pin provided on the automated guided travel device is inserted into the basket cart, and the crawling loading type, in which the cart is lifted by a lifting device provided on the automated guided travel device and transported. Of these, the loading type allows heavy objects to be transported regardless of the weight of the automated guided travel device itself, as the weight of the cart is applied to the body of the automated guided travel device, increasing the propulsive force of the wheels of the automated guided travel device.

When a lifting device combines a scissor link mechanism or a rack and pinion mechanism, the structure becomes large and complex, but there was an issue that setting a long stroke on a linear guide with a simple structure makes it difficult to make the lifting device compact.

In order to solve the above problem, Patent Document 1 describes a method for keeping the lifting device compact while using a linear drive source by providing a lift platform that supports the transported object, multiple hydraulic cylinders that support the lift platform and extend and retract to raise and lower the lift platform, and a telescopic linear guide that extends and retracts in multiple stages in the vertical direction between the multiple hydraulic cylinders as a mechanical synchronization mechanism. This ensures a sufficient lifting stroke for the lift platform even when the automated guided vehicle is a low-floor type.

Patent document 2 describes a transport vehicle that uses a cylinder with threads on the inside and outside of the cylinder and a screw jack to make the transport vehicle thinner while increasing the lift amount, and that can also withstand a heavy load.

However, in conventional systems, the lifting device has a large and complicated structure when a scissor link mechanism or rack and pinion mechanism is combined, and there is an issue that it is difficult to make the lifting device compact when a long stroke is set on a linear guide with a simple structure.

The present invention has been made in consideration of the above, and aims to provide a lifting device and a moving body that can be easily configured to be compact and that can easily ensure a lifting stroke.

In order to solve the above-mentioned problems and achieve the object, the lifting device of the present invention is a lifting device mounted on a moving body, and is characterized in that it comprises a support body, a drive shaft extending in the vertical direction, a drive motor supported by the support body, a female screw member rotated by the drive shaft, and a male screw member extending in the vertical direction, coupled with the female screw member, and movable in the vertical direction relative to the support body, a plurality of screw pairs arranged around the drive shaft and converting the rotational motion of the drive shaft into vertical movement of the male screw member, and two connecting members arranged at intervals in the vertical direction, connecting the plurality of male screw members, and moving in the vertical direction together with the plurality of male screw members.

The present invention has the effect of providing a lifting device and a moving body that can be easily made compact and that can easily ensure a lifting stroke.

FIG. 1 is a perspective view illustrating an example of a moving body and a dolly according to an embodiment. FIG. 2 is a perspective view illustrating an example of a moving body according to the embodiment. FIG. 3 is a perspective view illustrating an example of the moving body according to the embodiment, in which the loading plate is removed. FIG. 4 is a perspective view illustrating an example of the moving body according to the embodiment, in which the lifting device is removed. FIG. 5 is a side cross-sectional view illustrating an example of the lifting device according to the embodiment. FIG. 6 is a plan view illustrating an example of a portion including a lifting base of the lifting device according to the embodiment. FIG. 7 is a bottom view illustrating an example of the lifting device according to the embodiment.

The following describes in detail the embodiments of the lifting device and the moving body with reference to the attached drawings.

FIG. 1 is an exemplary perspective view of a moving body 100 and a dolly 300 according to an embodiment. As shown in FIG. 1, the moving body 100 can mount the dolly 300 on an elevating device 200. The moving body 100 is, for example, an unmanned guided vehicle. The dolly 300 is an example of an object to be lifted. In the following description, the up-down direction refers to the up-down direction of the moving body 100 and the elevating device 200.

The cart 300 has a frame 301 and a number of wheels 302. As an example, one wheel is provided on each of the front, rear, left and right parts of the cart 300. The wheels 302 are connected to the lower part of the frame 301.

Figure 2 is an exemplary perspective view of the moving body 100 according to the embodiment. Figure 3 is an exemplary perspective view of the moving body 100 according to the embodiment, with the loading plate 40 removed. Figure 4 is an exemplary perspective view of the moving body 100 according to the embodiment, with the lifting device 200 removed.

As shown in Figures 2 to 4, the moving body 100 includes a main body 29 and an elevating device 200 mounted on the main body 29. The main body 29 is capable of traveling, and the elevating device 200 is capable of raising and lowering the cart 300 while supporting the cart 300.

The main body 29 has a chassis 30, two drive wheels 31, 32, and a driven wheel 33. The chassis 30 is configured to have a low floor. A space (cavity) is provided in the center of the chassis 30 to accommodate the lifting device 200, and the chassis 30 is configured so that the drive motor 3 and the lower connecting plate 17 of the lifting device 200 do not interfere with each other when the lifting device is mounted. In addition, an opening 30a (Figure 4) is provided in the upper wall of the chassis 30, through which the lower connecting plate 17 of the lifting device 200 can pass.

As shown in FIG. 4, the two drive wheels 31 are supported by the chassis 30 at the center of the moving body 100 in the front-rear direction of the moving body 100. The two drive wheels 31, 32 are arranged to be able to rotate differentially with respect to each other. In other words, the two drive wheels 31, 32 can be rotated independently of each other. As an example, the two drive wheels 31, 32 are rotated by a motor provided for each drive wheel 31, 32.

The driven wheel 33 is positioned at a distance in the fore-and-aft direction from the two drive wheels 31, 32 and is supported by the chassis 30. There may be one or more driven wheels.

The moving body 100 configured as described above is capable of traveling forward and backward and spin turns. Such a moving body 100 can turn around the center of the chassis 30 as an axis, and can reduce the radius of rotation when turning. Note that in this embodiment, a differential two-wheel configuration is described as an example, but the present invention is not limited to this.

Figure 5 is a side cross-sectional view showing an example of the lifting device 200 according to the embodiment. Figure 6 is a plan view showing an example of a portion of the lifting device 200 according to the embodiment, including the lifting base 2. Figure 7 is a bottom view showing an example of the lifting device 200 according to the embodiment.

As shown in Figures 5 and 6, the lifting device 200 has a support body 1, a lifting base 2, a drive motor 3, a plurality of (four in one example) screw pairs 21-24, a transmission mechanism 26, a lower connecting plate 17, an upper connecting plate 18, and a loading plate 40. Note that the number of screw pairs 21-24 is not limited to the above. For example, the number of screw pairs 21-24 may be three, etc. In this embodiment, it can also be said that the number of screw pairs 21-24 is three or more.

The support 1 is fixed to the upper surface of the chassis 30. The support 1 is also called a structure or a frame.

The lifting base 2 is fixed to the upper part of the support 1. The lifting base 2 is formed in a flat shape that is thin in the vertical direction. The lifting base 2 is also called a lifting plate.

The drive motor 3 is disposed in the center of the lift base 2 and is supported by the lift base 2. That is, the drive motor 3 is supported by the support 1 via the lift base 2. The drive motor 3 has a main body 3a and a drive shaft 3b. The main body 3a includes a motor case and a stator. The drive shaft 3b extends in the vertical direction and protrudes upward from the main body 3a. The drive shaft 3b is rotatably supported by the main body 3a.

The screw pairs 21 to 24 are arranged around the drive shaft 3b. The screw pairs 21 to 24 each have a female screw member 9 to 12 and a male screw member 13 to 16.

The female screw members 9 to 12 are rotatably supported on the lifting base 2. That is, the female screw members 9 to 12 are rotatably supported on the support body 1 via the lifting base 2. The female screw members 9 to 12 are connected to the drive shaft 3b via the transmission mechanism 26. The female screw members 9 to 12 are rotated by the drive shaft 3b via the transmission mechanism 26. The female screw members 9 to 12 have a female screw portion formed on their inner circumferential surface. The female screw members are, for example, nuts.

The male screw members 13 to 16 extend in the vertical direction. In other words, the male screw members 13 to 16 are parallel to the drive shaft 3b. The male screw members 13 to 16 are connected to the female screw members 9 to 12, respectively. The male screw member 13 is provided so as to be movable in the vertical direction relative to the lift base 2 and the support body 1. The male screw members 13 to 16 are male screws or bolts, and have a male thread formed on the outer circumferential surface.

The screw pairs 21 to 24 convert the rotational motion of the drive shaft 3b into the up and down motion of the male screw members 13 to 16. The screw pairs 21 to 24 are also called the lifting mechanism.

The transmission mechanism 26 is interposed between the drive shaft 3b and the female screw members 9-12, and transmits the power of the drive shaft 3b to the female screw members 9-12. In detail, the transmission mechanism 26 has one drive gear 4 and multiple driven gears 5-8. The drive gear 4 is fixed to the drive shaft 3b and rotates integrally with the drive shaft 3b. The driven gears 5-8 are each fixed to the female screw members 9-12 with the female screw members 9-12 inserted on their inner periphery. The driven gears 5-8 are also engaged with the drive gear 4. The drive gear 4 and the driven gears 5-8 are examples of gears.

The lower connecting plate 17 and the upper connecting plate 18 are arranged at intervals in the vertical direction and connect the male screw members 13 to 16. In other words, the male screw members 13 to 16 are integrated by the lower connecting plate 17 and the upper connecting plate 18. The lower connecting plate 17 is fixed to the lower ends of the multiple male screw members 13 to 16. The upper connecting plate 18 is located above the lower connecting plate 17. The upper connecting plate 18 is fixed to the upper ends of the multiple male screw members 13 to 16. The lower connecting plate 17 and the upper connecting plate 18 move in the vertical direction together with the male screw members 13 to 16. The lower connecting plate 17 and the upper connecting plate 18 are an example of two connecting members, the lower connecting plate 17 is an example of a lower connecting member, and the upper connecting plate 18 is an example of an upper connecting member.

In the above configuration, when the drive shaft 3b of the drive motor 3 rotates, the power of the drive shaft 3b is transmitted to the female screw members 9-12 via the drive gear 4 and the driven gear 5, and the female screw members 9-12 rotate. That is, the female screw members 9-12 rotate in sync with the rotation of the drive shaft 3b of the drive motor 3. When the female screw members 9-12 rotate, the male screw members 13-16 move up and down according to the direction of rotation. At this time, the lower connecting plate 17 and the upper connecting plate 18 move up and down, i.e., rise and fall, together with the male screw members 13-16. The male screw members 13-16, the lower connecting plate 17, and the upper connecting plate 18 can rise to a position where the lower connecting plate 17 comes into contact with the lift base 2 in the up and down direction. This allows the lift stroke to be utilized to the fullest.

As shown in FIG. 5, the lower connecting plate 17 has an opening 17a. The drive motor 3 is inserted into the opening 17a. The opening 17a allows the lower connecting plate 17 and the drive motor 3 to move relative to each other in the vertical direction. The lower connecting plate 17 and the drive shaft 3b are spaced apart from each other even when they move relative to each other. In other words, the lower connecting plate 17 and the drive shaft 3b do not interfere with each other even when they move relative to each other.

The lower connecting plate 17 is fitted into the space in the chassis 30. This ensures a sufficient stroke for the lifting device while keeping the moving body 100 on the bottom floor.

As shown in Figs. 5 and 7, a plate-shaped light-shielding portion 20 is fixed to the lower connecting plate 17. The light-shielding portion 20 moves vertically together with the lower connecting plate 17. The light-shielding portion 20 is also called a light-shielding plate.

As shown in FIG. 5, the lifting device 200 has a transmission sensor 19 and a rotation speed sensor 25. As shown in FIGS. 5 and 7, the transmission sensor 19 is fixed to the lifting base 2. As shown in FIG. 7, the transmission sensor 19 has a light-projecting portion 19a and a light-receiving portion 19b that is spaced apart from the light-projecting portion 19a in a direction intersecting (for example, perpendicular to) the up-down direction. The light-projecting portion 19a projects (emits) light to the light-receiving portion 19b. The light-receiving portion 19b receives the light projected from the light-projecting portion 19a. The light-shielding portion 20, which moves up and down, passes through the gap (slit) between the light-projecting portion 19a and the light-receiving portion 19b.

The rotation speed sensor 25 is provided on the drive motor 3. The rotation speed sensor 25 measures the rotation speed of the drive shaft 3b.

In the above configuration, the position of the drive shaft 3b when the light blocking portion 20 passes the transmission sensor 19 is set as the reference position, and the number of rotations of the drive shaft 3b of the drive motor 3 from that position is measured by the rotation speed sensor 25, thereby making it possible to measure the number of rotations of the female screw members 9 to 12. The amount of movement of the female screw members 9 to 12 can be estimated from the number of rotations and the amount of up and down movement per rotation of the female screw members 9 to 12. Therefore, the amount of lift can be controlled without using a position detection sensor such as a potentiometer.

The loading plate 40 shown in FIG. 2 is disposed above the upper connecting plate 18 and fixed to the upper connecting plate 18. The loading plate 40 moves vertically together with the upper connecting plate 18. The loading plate 40 is formed in a plate shape. The dolly 300 is loaded on the upper surface of the loading plate 40. The area of the upper surface of the loading plate 40 is larger than the area of the upper surface of the upper connecting plate 18. In other words, the loading plate 40 has a larger shape in the direction intersecting the vertical direction than the upper connecting plate 18. In this way, by loading the dolly 300 on the loading plate 40, the dolly 300 can be supported by the relatively wide upper surface of the loading plate, and the dolly 300 can be transported while stabilizing the posture of the dolly 300. The loading plate 40 is also called a support base or support plate.

Two limiting sections 41, one on each side, are provided at the front end of the upper surface of the loading plate 40. The number of limiting sections 41 is not limited to two. The limiting sections 41 are formed in a concave shape that opens upward, and support the frame 301 of the cart 300. The limiting sections 41 support the frame 301 of the cart 300 and limit the movement of the cart 300 relative to the loading plate 40 in a direction that intersects with the up-down direction (for example, the left-right direction of the moving body). The limiting sections 41 are also referred to as support members or holding members.

As described above, the lifting device 200 of this embodiment is mounted on the moving body 100. The lifting device 200 includes the support 1, the drive motor 3, multiple screw pairs 21-24, and the lower connecting plate 17 and upper connecting plate 18 (two connecting members). The drive motor 3 has a drive shaft 3b extending in the vertical direction and is supported by the support 1. Each of the multiple screw pairs 21-24 has female screw members 9-12 rotated by the drive shaft 3b, and male screw members 13-16 that extend in the vertical direction, are coupled with the female screw members 9-12, and can move in the vertical direction relative to the support 1. The multiple screw pairs 21-24 are arranged around the drive shaft 3b, and convert the rotational movement of the drive shaft 3b into vertical movement of the male screw members 13-16. The lower connecting plate 17 and the upper connecting plate 18 are arranged vertically at intervals, connect the multiple male screw members 13 to 16, and move vertically together with the multiple male screw members 13 to 16.

With this configuration, it is possible to obtain a lifting device 200 and a moving body 100 that are space-saving and have a sufficient lifting stroke. The above configuration can be said to be a mechanism that can withstand a high load with sufficient vertical lifting stroke with a simple configuration with a small number of parts required for the lifting operation. Furthermore, with the above configuration, it is possible to realize a lifting device 200 that can stably lift heavy loads with a simple, low-floor configuration.

In addition, in this embodiment, the drive gear 4, driven gears 5-8, and female screw members 9-12 are provided on the upper side of the lift base 2, but by using thin materials for the top and bottom of these components, the lift base 2 can be configured to be compact in the vertical direction. By making the lift base 2 compact, a large vertical stroke can be achieved without using telescopic guides or screws, and a sufficient stroke can be ensured with a simple component configuration. Note that, although the rotation transmission mechanism has been described using gears in this embodiment, the form of the transmission mechanism is not limited to this.

In addition, in this embodiment, a lower connecting plate 17 is attached to the lower ends of the male screw members 13-16, and an upper connecting plate 18 is attached to the upper ends, thereby integrating the four male screw members 13-16. By sandwiching and fixing the male screw members 13-16 between the upper and lower connecting plates (lower connecting plate 17 and upper connecting plate 18) in this way, high rigidity can be maintained and heavy objects can be stably loaded. Also, by providing the male screw members 13-16 in four places without using a guide, the upper connecting plate 18 (lifting plate) can be lifted with a surface, allowing heavy objects to be lifted and lowered stably.

In addition, in this embodiment, the lower connecting plate 17 of the lower connecting plate 17 and the upper connecting plate 18 has an opening 17a into which the drive motor 3 is inserted and which allows relative movement between the lower connecting plate 17 and the drive motor 3 in the vertical direction.

With this configuration, the lower connecting plate 17 does not interfere with the drive motor 3, ensuring a large vertical stroke for the lifting operation of the lifting device 200.

In addition, in this embodiment, the lifting device 200 includes a drive gear 4 and a driven gear 5 (gears) that are interposed between the drive shaft 3b and the female screw members 9 to 12 and transmit the power of the drive shaft 3b to the female screw members 9 to 12.

With this configuration, by using the drive gear 4 and driven gear 5 as the power transmission members between the drive shaft 3b and the female screw members 9 to 12, it is possible to construct a lifting device 200 that has a relatively small number of parts and is thin both vertically and vertically.

In this embodiment, the lifting device 200 also includes a rotation speed sensor 25, a transmission sensor 19, and a light shielding section 20 (light shielding section). The rotation speed sensor 25 measures the rotation speed of the drive shaft 3b. The transmission sensor 19 is supported by the support body 1 and has a light projecting section 19a and a light receiving section 19b that is spaced apart from the light projecting section 19a in a direction intersecting the vertical direction. The light shielding section 20 moves vertically together with the male screw members 13 to 16, passing between the light projecting section 19a and the light receiving section 19b.

With this configuration, the height of the upper connecting plate 18 (lifting plate) is measured from the detection results of the transmission sensor 19 and the detection results of the rotation speed sensor 25 (the rotation speed of the drive shaft 3b of the drive motor 3), eliminating the need to install a sensor that measures height, such as a potentiometer. Therefore, the amount of lift of the upper connecting plate 18 can be measured with a space-saving configuration.

In this embodiment, the lifting device 200 includes a loading plate 40 and a limiting section 41. The loading plate 40 is supported by the upper connecting plate 18 out of the lower connecting plate 17 and the upper connecting plate 18, moves vertically together with the upper connecting plate 18, has a larger shape (area of the upper surface) in a direction intersecting the vertical direction than the upper connecting plate 18, and carries a trolley 300 (an object to be lifted and lowered). The limiting section 41 is provided on the loading plate 40, supports the trolley 300, and limits the movement of the trolley 300 relative to the loading plate 40 in a direction intersecting the vertical direction.

This configuration allows the cart 300 to be raised and lowered stably.

The mobile body 100 of this embodiment is capable of traveling. The mobile body 100 includes a lifting device 200 and a chassis 30 that supports the lifting device 200 and has an opening 30a through which the lower connecting plate 17 of the lower connecting plate 17 and the upper connecting plate 18 can pass.

With this configuration, the chassis 30 is provided with an opening 30a through which the lower connecting plate 17 can pass, so that the height of the moving body 100 and the lifting device 200 can be reduced while the vertical stroke of the lifting device 200 can be increased.

In this embodiment, the moving body 100 is equipped with two drive wheels 31, 32 and one or more driven wheels 33. The drive wheels 31, 32 are supported by the chassis 30 at the center of the moving body 100 in the fore-aft direction of the moving body 100, and can be driven independently of each other. The driven wheel 333 is positioned at a distance from the two drive wheels 31, 32 in the fore-aft direction and is supported by the chassis 30.

With this configuration, the moving body 100 can rotate around the center of the chassis 30, so the radius of rotation of the moving body 100 can be reduced.

The above-described embodiment is presented as an example, and is not intended to limit the scope of the present invention. This new embodiment can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. Furthermore, the embodiment and modifications of the embodiment are included within the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

1... Support body 3... Drive motor 3b... Drive shaft 4... Drive gear (gear)
5...Driven gear (gear)
9 to 12: Female screw members 13 to 16: Male screw members 17: Lower connecting plate (connecting member)
17a...Opening 18...Upper connecting plate (connecting member)
19: Transmissive sensor 19a: Light-emitting section 19b: Light-receiving section 20: Light-shielding section 21 to 24: Screw pair 25: Rotational speed sensor 30: Chassis 30a: Opening 31, 32: Driving wheel 33: Driven wheel 40: Loading plate 41: Limiting section 100: Moving body 200: Lifting device

Patent No. 3091912 JP 2018-34932 A

Claims (7)

An elevator device mounted on a moving body,
A support;
a drive motor having a drive shaft extending in the vertical direction and supported by the support;
A plurality of screw pairs each having a female screw member rotated by the drive shaft and a male screw member extending in the vertical direction and coupled with the female screw member and movable in the vertical direction relative to the support body, the screw pairs being arranged around the drive shaft and converting the rotational motion of the drive shaft into vertical movement of the male screw member;
Two connecting members arranged at intervals in the vertical direction, connecting the plurality of male screw members, and moving in the vertical direction together with the plurality of male screw members;
A lifting device comprising: The drive motor is inserted into the lower connecting member of the two connecting members, and an opening is provided to allow relative movement between the lower connecting member and the drive motor in the vertical direction.
The lifting device according to claim 1 . A gear is provided between the drive shaft and the female screw member to transmit the power of the drive shaft to the female screw member.
The lifting device according to claim 1 . A rotation speed sensor that measures the rotation speed of the drive shaft;
a transmission type sensor supported by the support body and having a light projecting unit and a light receiving unit provided at an interval in a direction intersecting the vertical direction with the light projecting unit;
a light-shielding portion that moves in the up-down direction together with the male screw member and passes between the light-projecting portion and the light-receiving portion;
The lifting device according to claim 1 , comprising: a loading plate supported by an upper one of the two connecting members, movable in the up-down direction together with the upper connecting member, having a larger shape in a direction intersecting the up-down direction than the upper connecting member, and on which an object to be lifted or lowered is loaded;
a limiting portion provided on the loading plate, supporting the lifting object and limiting movement of the lifting object relative to the loading plate in a direction intersecting the up-down direction;
The lifting device according to claim 1 , comprising: A movable body capable of running,
The lifting device according to claim 1 ;
a chassis having an opening through which the lower one of the two connecting members can pass and supporting the lifting device;
A mobile body equipped with the above. Two drive wheels supported by the chassis at a central portion of the movable body in a front-rear direction of the movable body and capable of being driven independently of each other;
one or more driven wheels positioned at intervals in the front-rear direction relative to the two driving wheels and supported by the chassis;
The moving body according to claim 6 .

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