Auxiliary wheel device and hand-pushed carrier

Abstract

To reduce a load due to a heavy muscular work by a worker when a hand-pushed carrier is caused to run.SOLUTION: An auxiliary wheel device is attached to a hand-pushed carrier that includes a load carrying platform, wheels, and a vehicular body including a pair of handle portions. The auxiliary wheel device includes an auxiliary wheel and an extendable mechanism. The extendable mechanism has a lower end portion connected to the auxiliary wheel, is attached to the rear side relative to the load carrying platform of the vehicular body, and is structured so as to extend and contract in the vertical direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a training wheel device and a stroller. [Background technology]

[0002] Conventionally, for example, at agricultural, civil engineering, or construction sites, there is known a pushcart that is pushed by a worker while traveling with materials or other cargo loaded on the platform. Patent Document 1 discloses a three-wheeled electric pushcart. The pushcart disclosed in Patent Document 1 has front wheels with built-in motors and left and right rear wheels that are caster-type idler wheels. Patent Document 1 also discloses a four-wheeled electric pushcart.

[0003] Moreover, a one-wheeled electric-assisted transport vehicle is disclosed in Patent Document 2. In the electric-assisted transport vehicle disclosed in Patent Document 1, a motor that drives the wheel is controlled by a grip operation by an operator. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-218092 A [Patent Document 2] Japanese Patent Application Publication No. 11-263227 Summary of the Invention [Problem to be solved by the invention]

[0005] When a pushcart is used to transport luggage, the worker must hold a pair of handles extending rearward from both sides of the platform and lift the rear end of the pushcart upward while driving the pushcart. In such a case, if the luggage is heavy, the heavy physical labor of lifting the rear end of the pushcart may be a burden for the worker.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a technique that can reduce the burden on an operator from the heavy physical work required when driving a hand truck. [Means for solving the problem]

[0007] The training wheel device according to a first aspect of the present invention is an training wheel device attached to a pushcart having a cargo bed, wheels located below the cargo bed, and a body to which the cargo bed and wheels are attached and which includes a pair of handle portions extending rearward from both sides of the cargo bed, and comprises an training wheel and an extension mechanism whose lower end is connected to the training wheel and which is attached to the body rearward of the cargo bed and is configured to extend and retract in the vertical direction.

[0008] The training wheel device according to the first aspect of the present invention is a device to be attached to a cart. This training wheel device includes training wheels and a telescopic mechanism. In the training wheel device, the training wheels are connected to the lower end of the telescopic mechanism. The telescopic mechanism is attached to the body of the cart behind the loading platform. In other words, the training wheel device is attached to the handle side of the cart. And the cart to which the training wheel device is attached can run using the training wheels and the wheels located below the loading platform.

[0009] The telescopic mechanism of the auxiliary wheel device is configured to telescope in the vertical direction. When the telescopic mechanism, which is attached to the rear of the loading platform on the body of the transport vehicle, telescopes in the vertical direction, the inclination angle of the body is changed. More specifically, when the telescopic mechanism is driven in the extending direction, the wheels and the auxiliary wheels are When the telescopic mechanism is driven in the retracting direction, the inclination angle (rear tilt angle) of the vehicle body relative to the horizontal plane on which the wheels and auxiliary wheels are on the ground becomes larger. As a result, the rear of the cart (handle side) rises upward. Conversely, when the telescopic mechanism is driven in the retracting direction, the inclination angle (rear tilt angle) of the vehicle body relative to the horizontal plane on which the wheels and auxiliary wheels are on the ground becomes smaller. As a result, the rear of the cart (handle side) drops downward.

[0010] As described above, the training wheel device according to the first aspect of the present invention makes it possible to eliminate or assist the heavy physical work of an operator lifting the rear end of a cart with luggage loaded on the platform by driving the telescopic mechanism in the extension direction. This makes it possible to reduce the burden of heavy physical work on the operator when traveling the cart with the rear end lifted.

[0011] The auxiliary wheel device according to the first aspect of the present invention may further include an operation unit that operates the drive of the telescopic mechanism, the operation unit being installed on the handle portion of the vehicle body.

[0012] Furthermore, the training wheel device according to the first aspect of the present invention may further include an air cylinder in the telescopic mechanism, a compressor that supplies air to the air cylinder, and an exhaust valve that exhausts air from the air cylinder, and the telescopic mechanism may be telescopically extended or retracted by controlling the compressor and the exhaust valve with the operating unit.

[0013] A stroller according to a second aspect of the present invention is a stroller equipped with the training wheel device according to the first aspect of the present invention.

[0014] According to the second aspect of the present invention, the heavy physical labor required by an operator to lift the rear end of the cart with luggage loaded on the platform can be eliminated or assisted by driving the extension mechanism of the auxiliary wheel device in the extension direction. This reduces the burden on the operator of the heavy physical labor required to drive the cart with the rear end lifted.

[0015] In addition, in the hand transport vehicle according to the second aspect of the present invention, the wheel may be a single wheel, and the auxiliary wheel device may be attached to the vehicle body so that the auxiliary wheel is aligned in approximately a straight line in the fore-and-aft direction with the wheel.

[0016] In addition, in the second aspect of the present invention, the auxiliary wheel devices may be attached to the vehicle body so that, when viewed from the side of the telescopic mechanism, the angle between the horizontal plane on which the wheels of the cart are in contact with the ground and the central axis of the telescopic mechanism is an acute angle at the rear of the cart when the telescopic mechanism is in its most retracted state.

[0017] In the hand cart according to the second aspect of the present invention, the wheels may be driven by electricity. Effect of the Invention

[0018] According to the present invention, the burden on an operator due to heavy physical work when driving a hand truck can be reduced. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a pushcart as viewed from the side. [Diagram 2] FIG. 2 is a diagram showing a schematic configuration of the hand truck when viewed from above. [Diagram 3] FIG. 3 is a diagram showing the positional relationship between the wheels and the auxiliary wheels when the cart is viewed from above. [Figure 4] Fig. 4(A) is a diagram showing the state of the cart loaded with luggage when the telescopic mechanism is fully retracted, and Fig. 4(B) is a diagram showing the state of the cart loaded with luggage when the telescopic mechanism is fully extended. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, specific embodiments of the present disclosure will be described with reference to the drawings. The dimensions, materials, shapes, and relative positions of the components described in the present embodiments are not intended to limit the technical scope of the present disclosure unless otherwise specified.

[0021] <Embodiment> (Schematic configuration) 1 to 3 are diagrams for explaining the schematic configuration of a hand truck and an auxiliary wheel device according to this embodiment. FIG. 1 is a diagram showing the schematic configuration of a hand truck (hereinafter sometimes referred to as a "truck") 1 as viewed from the side. In FIG. 1, part of the configuration of the auxiliary wheel device 100 is represented by symbols for convenience. Also, in FIG. 1, part of the auxiliary wheel device 100 is shown in cross section. Also, in FIG. 1, part of the body 3 of the truck 10 is omitted in order to illustrate the configuration of the auxiliary wheel device 100.

[0022] Fig. 2 is a diagram showing a schematic configuration of the transporter 10 when viewed from above. Fig. 3 is a diagram showing the positional relationship between the wheel 2 of the transporter 10 and the auxiliary wheel 101 of the auxiliary wheel device 100 when viewed from above. In Figs. 1 to 3, the left side of the drawings is the front and the right side is the rear. Fig. 1 is a diagram showing the transporter 10 as viewed from the direction of the outline arrow in Fig. 2 (i.e., the left side).

[0023] The transport vehicle 10 has a loading platform 1, one wheel 2, and a vehicle body 3. The loading platform 1 is loaded with luggage, which is the object to be transported by the transport vehicle 10. The wheel 2 is located below the loading platform 1. The wheel 2 is located at the center of the transport vehicle 10 in the left-right direction. The wheel 2 has a built-in motor 21. The motor 21 is a so-called in-wheel motor that rotates the wheel 2. The loading platform 1 and the wheel 2 are attached to the vehicle body 3. In Figs. 2 and 3, the loading platform 1 is shown by a dashed line for the convenience of illustrating the wheel 2 and the vehicle body 3.

[0024] The vehicle body 3 includes a pair of handle frames 31, a bed frame 32, a wheel frame 33, a ground contact frame 34, and a mounting frame 35. The bed frame 32 has a substantially U-shape in a plan view, and the bed 1 is connected to it. The wheel frame 33 is connected to the bed frame 32. The wheels 2 are connected to the wheel frame 33.

[0025] A pair of handle frames 31 are connected to the bed frame 32. The pair of handle frames 31 are connected to the ends of the bed frame 32, respectively, and extend rearward from both sides of the bed 1. When using the transporter 10, the operator holds the handle frame 31 with both hands and lifts it upward while pushing the transporter 10 to move it. As shown in Figs. 2 and 3, when the pair of handle frames 31 are to be distinguished between the right handle frame and the left handle frame, they are referred to as the right handle frame 31a and the left handle frame 31b, respectively. In this embodiment, the handle frame 31 corresponds to the "handle portion" according to the present invention.

[0026] A ground frame 34 is connected to the platform frame 32 and the pair of handle frames 31. When the transporter 10 is placed on the ground, the ground frame 34 touches the ground rearward of the wheels 2. In other words, as shown in Fig. 1, when the operator releases his / her hands from the transporter 10, the transporter 10 is supported by the wheels 2 and the ground frame 34. Note that in Fig. 1, In order to illustrate the configuration of the auxiliary wheel device 100, a part of the ground contact frame 34 is omitted.

[0027] A mounting frame 35 is connected to a portion of the handle frame 31 near the platform 1 so as to straddle the right handle frame 31a and the left handle frame 31b. A battery 4 that supplies power to the motor 21 built into the wheel 2 and a controller 5 that controls the power supply from the battery 4 to the motor 21 are mounted on the mounting frame 35. In other words, the transporter 10 is an electrically assisted transporter that can assist the motor 21 in driving the transporter when pushed by an operator. In FIG. 3, the mounting frame 35 is indicated by a dashed line for the convenience of illustrating the auxiliary wheels 101.

[0028] Further, a first operating unit 6 that is operated by an operator is provided on the right handle frame 31a. The first operating unit 6 is an operating unit for operating the drive of the motor 21. When the first operating unit 6 is operated by the operator, the drive of the motor 21 is controlled via the controller 5. Therefore, by operating the first operating unit 6, the operator can rotate the wheels 2 in the forward or backward direction by the motor 21, or adjust the rotation speed of the wheels 2 by the motor 21.

[0029] In this embodiment, an auxiliary wheel device 100 is attached to the transporter 10. The auxiliary wheel device 100 includes auxiliary wheels 101 and a telescopic mechanism 102. The telescopic mechanism 102 is a mechanism that can be extended and retracted in the vertical direction. This telescopic mechanism 102 is attached to the mounting frame 35 of the transporter 10. In other words, the telescopic mechanism 102 is attached to the body 3 of the transporter 10, rearward of the platform 1. The telescopic mechanism 102 includes an air cylinder 1021. The telescopic mechanism 102 may also include a built-in shock absorber.

[0030] Auxiliary wheels 101 are connected to the lower end of the telescopic mechanism 102. The auxiliary wheels 101 are connected to the telescopic mechanism 102 so as to be rotatable around the central axis thereof. As shown in FIG. 3, the telescopic mechanism 102 is attached to the mounting frame 35 so that the auxiliary wheels 101 are aligned substantially in a straight line with the wheels 2 in the front-rear direction. Therefore, like the wheels 2, the auxiliary wheels 101 are also located at the center of the transporter 10 in the left-right direction. When the operator drives the transporter 10, the transporter 10 drives using the wheels 2 and the auxiliary wheels 101.

[0031] The mounting frame 35 is provided with a compressor 103 for supplying air to the air cylinder 1021 of the telescopic mechanism 102. The battery 4 supplies power to the compressor 103. The mounting frame 35 is provided with an air passage 104 for supplying air from the compressor 103 to the air cylinder 1021. The air passage 104 is provided with a check valve 105 for preventing air from flowing back from the air cylinder 1021 to the compressor 103. An exhaust valve 106 for exhausting air from the air cylinder 1021 is provided downstream of the check valve 105 in the air passage 104. The supply of power from the battery 4 to the compressor 103 and the opening and closing of the exhaust valve 106 are controlled by the controller 5. In FIG. 2, the air passage 104, the check valve 105, and the exhaust valve 106 are not shown.

[0032] When air is supplied from the compressor 103 to the air cylinder 1021 with the exhaust valve 106 closed, the telescopic mechanism 102 extends. On the other hand, when the exhaust valve 106 is opened and air is exhausted from the air cylinder 1021, the telescopic mechanism 102 contracts. Therefore, by controlling the compressor 103 and the exhaust valve 106, the telescopic mechanism 102 can be expanded or contracted.

[0033] A second operating unit 107 that is operated by an operator is provided on the left handle frame 31b. The second operating unit 107 is an operating unit for operating the drive of the telescopic mechanism 102. The second operation unit 107 may have a configuration in which the telescopic mechanism 102 is extended or retracted by, for example, a button operation. When the second operation unit 107 is operated by an operator, the drive of the compressor 103 and the exhaust valve 106 is controlled via the controller 5. Therefore, the operator can extend or retract the telescopic mechanism 102 by operating the second operation unit 107.

[0034] As described above, the telescopic mechanism 102 is attached to the vehicle body 3 behind the platform 1. The inclination angle of the vehicle body 3 is changed by the telescopic mechanism 102 extending and retracting. Here, the state of the transporter 10 when the telescopic mechanism 102 extends and retracts will be described with reference to FIG. 4. FIGS. 4(A) and 4(B) show the state of the transporter 10 with the platform 1 loaded with luggage. FIG. 4(A) is a diagram showing the state of the transporter 10 when the telescopic mechanism 102 is at its most retracted. Note that the state of the telescopic mechanism 102 when the ground frame 34 of the transporter 10 is in contact with the ground is defined as the state in which the telescopic mechanism 102 is at its most retracted. In other words, when the telescopic mechanism 102 is at its most retracted, the piston is not necessarily at its most upper end in the air cylinder 1021. FIG. 4(B) is a diagram showing the state of the transporter 10 when the telescopic mechanism 102 is extended. 4(A) and (B), the inclination angle (inclination angle on the rear side) of the vehicle body 3 with respect to the horizontal plane (ground) on which the transporter 10 is on the ground is indicated by α1 and α2. Note that the inclination angle of the portion of the platform frame 32 of the vehicle body 3 to which the bottom surface of the platform 1 is connected is defined as the inclination angle of the vehicle body 3. Also, in Fig. 4(A) and (B), as in Fig. 1, a portion of the ground frame 34 is omitted in order to illustrate the configuration of the training wheel device 100.

[0035] As shown in FIG. 4(B), when the telescopic mechanism 102 is extended, the inclination angle of the vehicle body 3 becomes larger than when the telescopic mechanism 102 is fully retracted as shown in FIG. 4(A). That is, the angle α2 in FIG. 4(B) becomes larger than the angle α1 in FIG. 4(A). As a result, the inclination angle (inclination angle of the rear side) of the handle frame 31 with respect to the horizontal plane (ground) on which the transporter 10 is in contact also becomes larger. Therefore, the rear side of the transporter 10 (i.e., the handle frame 31 side) is lifted upward. As a result, the ground contact frame 34 moves away from the ground.

[0036] In addition, in Fig. 4(A) and (B), the angle (rear tilt angle) between the horizontal plane (ground) on which the transporter 10 is in contact with the ground and the central axis of the telescopic mechanism 102 is indicated by β1 and β2. In this embodiment, as shown in Fig. 4(A), the telescopic mechanism 102 is attached to the vehicle body 3 so that the angle β1 is an acute angle when the telescopic mechanism 102 is in the most retracted state. At this time, the telescopic mechanism 102 is inclined rearward so that the upper part is located further rearward than the lower part. Then, as shown in Fig. 4(B), when the telescopic mechanism 102 is extended, the angle (rear tilt angle) between the horizontal plane (ground) on which the transporter 10 is in contact with the ground and the central axis of the telescopic mechanism 102 is also larger than when the telescopic mechanism 102 is in the most retracted state as shown in Fig. 4(A). In other words, the angle β2 in Fig. 4(B) is larger than the angle β1 in Fig. 4(A). At this time, the angle β2 can be an approximately right angle or an obtuse angle. However, even if the angle β2 is an acute angle when the telescopic mechanism 102 is extended, the rear side of the transporter 10 can be lifted upward compared to when the telescopic mechanism 102 is fully retracted.

[0037] (Action and effect) In the transport vehicle 10 according to this embodiment, when the telescopic mechanism 102 of the auxiliary wheel device 100 is driven in the extending direction, the inclination angle of the body 3 with respect to the horizontal plane on which the wheels 2 and auxiliary wheels 101 are in contact with the ground increases, and the rear of the transport vehicle 10 is lifted upward. Conversely, when the telescopic mechanism 102 is driven in the retracting direction, the inclination angle of the body 3 with respect to the horizontal plane on which the wheels 2 and auxiliary wheels 101 are in contact with the ground decreases, and the rear of the transport vehicle 10 drops downward.

[0038] Therefore, when a worker drives the transport vehicle 10 with the cargo loaded on the loading platform 1, the telescopic mechanism 102 is driven in the direction in which the telescopic mechanism 102 extends, so that the rear of the transport vehicle 10 is lifted up. This makes it possible to eliminate or assist the worker in lifting the rear end of the transport vehicle 10 with the cargo loaded on the loading platform 1. This reduces the burden on the worker in lifting the rear end of the transport vehicle 10 when the transport vehicle 10 is traveling with the rear end of the transport vehicle 10 lifted upward.

[0039] In addition, the telescopic mechanism 102 is configured so that the angles β1 and β2 between the horizontal plane (ground) on which the transporter 10 is in contact with the ground and the central axis of the telescopic mechanism 102 form angles as shown in Figs. 4(A) and (B). When the telescopic mechanism 102 is extended and the vehicle body 3 is tilted with a load placed on the platform 1, the angle β2 shown in Fig. 4(B) can be made approximately a right angle. By making the angle β2 approximately a right angle, the direction of the load applied to the telescopic mechanism 102 due to the weight of the load becomes the same as the direction of the central axis of the telescopic mechanism 102. This reduces the burden on the telescopic mechanism 102 in the extended state. However, the angles between the horizontal plane (ground) on which the transporter 10 is in contact with the ground and the central axis of the telescopic mechanism 102 are not limited to the angles β1 and β2 as shown in Figs. 4(A) and (B). In other words, even if the telescopic mechanism 102 is attached to the mounting frame 35 of the transporter 10 at an angle different from these, it is possible to lift the rear side of the transporter 10 upward by driving the telescopic mechanism 102 in the extension direction.

[0040] In addition, in the transport vehicle 10 according to this embodiment, the auxiliary wheel device 100 is attached to the vehicle body 3 so that the auxiliary wheel 101 is aligned substantially in a straight line with one wheel 2 in the front-rear direction. This allows the operator to drive the transport vehicle 10 using the wheel 2 and the auxiliary wheel 101 even in a place where the width of the road on which the transport vehicle 10 is traveling is narrow. In addition, in the transport vehicle 10, the auxiliary wheel 101 is connected to the extension mechanism 102 so as to be rotatable around the central axis of the extension mechanism 102, which improves the maneuverability of the transport vehicle 10 when the transport vehicle 10 is driven by the wheel 2 and the auxiliary wheel 101.

[0041] (Modification) In the above embodiment, the transport vehicle 10 is an electric-assisted transport vehicle, but this is not necessarily required. In other words, the auxiliary wheel device 100 may be attached to a transport vehicle that does not have an electric function. In this case, the battery 4 and the controller 5 are dedicated devices for driving the extension mechanism 102 of the auxiliary wheel device 100. However, when the transport vehicle 10 is an electric-assisted transport vehicle, its weight tends to be heavier than that of a transport vehicle that does not have an electric function. Therefore, when the transport vehicle 10 is driven with the rear end of the transport vehicle 10 raised, the worker is likely to be burdened by heavy muscle work. Therefore, by attaching the auxiliary wheel device 100 to the transport vehicle 10 that is an electric-assisted transport vehicle, the effect of reducing the burden on the worker when the transport vehicle 10 is driven with the rear end of the transport vehicle 10 raised is greater.

[0042] Moreover, the motor that drives the wheels 2 of the transporter 10 does not necessarily have to be an in-wheel motor. In other words, a motor may be provided in the transporter 10 separately from the wheels 2. Moreover, while the transporter 10 is traveling, the load of the motor that drives the wheels 2 may be fed back to the controller 5 to control the power supplied to the motor so that the traveling speed of the transporter 10 is kept substantially constant regardless of the weight of the baggage loaded on the platform 1. Moreover, the drive of the wheels 2 may be inverter-controlled to suppress sudden starts or stops of the transporter 10.

[0043] The transporter 10 may also be provided with a remaining battery power meter for the battery 4. The battery 4 mounted on the mounting frame 35 may be configured to be removable. The battery 4 and various devices such as the controller 5 mounted on the mounting frame 35, as well as the first operating unit 6 and the second operating unit 107 mounted on the handle frame 31, may have waterproof, dustproof, and dirt-proof functions. The first operating unit 6 and the second operating unit 107 may also be disposed on the handle frame 31 at positions that allow the operator to operate them while gripping the handle portion of the handle frame 31. The first operating unit 6 and the second operating unit 107 may also be disposed on the handle frame 31 at positions that allow the operator to operate them while gripping the handle portion of the handle frame 31. The controller 5 may have a structure that allows the user to operate the wheel 2 and the telescopic mechanism 102 while gripping the handle 104. The controller 5 may have a memory function for each user in order to control the driving of the wheel 2 and the telescopic mechanism 102 according to each user.

[0044] The number of auxiliary wheels in the auxiliary wheel device 100 does not necessarily have to be one. For example, the auxiliary wheel device 100 may have two auxiliary wheels arranged side by side facing each other with the central axis of the telescopic mechanism 102 in between. The controller 5 may also control the speed at which air is supplied from the compressor 103 to the air cylinder 1021 of the telescopic mechanism 102, and the speed at which air is exhausted from the air cylinder 1021 by the exhaust valve 106. This makes it possible to control the telescopic speed of the telescopic mechanism 102.

[0045] In addition, a device for supplying air to the air cylinder 1021 is not limited to the compressor 103. In addition, the extension mechanism 102 may have a mechanism other than the air cylinder 1021. For example, the extension mechanism 102 may be a mechanism that is extended and contracted by an electric actuator. [Explanation of symbols]

[0046] 1...Cargo platform 10. Transport vehicle 2...wheels 21 Motor 3. Body 31 Handle frame 4. Battery 5. Controller 6...1st operation section 100...Training wheel device 101 Training wheels 102...Extension mechanism 1021 Air cylinder 103··Compressor 104 Air passage 105 Check valve 106 Exhaust valve 107...Second operation section

Claims

1. 1. An auxiliary wheel device to be attached to a hand truck having a platform, wheels positioned below the platform, and a vehicle body to which the platform and wheels are attached and which includes a pair of handles extending rearward from both sides of the platform, Training wheels and a telescopic mechanism having a lower end connected to the auxiliary wheels, attached to the vehicle body rearward of the loading platform, and configured to telescopically extend and retract in a vertical direction; An auxiliary wheel device comprising:

2. An operation unit for operating the telescopic mechanism is further provided, the operation unit being installed on the handle portion of the vehicle body.

2. The auxiliary wheel device according to claim 1.

3. The telescopic mechanism includes an air cylinder, A compressor that supplies air to the air cylinder; and an exhaust valve for exhausting air from the air cylinder. The compressor and the exhaust valve are controlled by the operating unit to expand and contract the expansion mechanism.

3. The auxiliary wheel device according to claim 2.

4. A hand truck having the auxiliary wheel device according to any one of claims 1 to 3 attached thereto.

5. The wheel is one wheel, The auxiliary wheel device is attached to the vehicle body so that the auxiliary wheel is aligned substantially in a straight line with the wheel in the front-rear direction.

5. A cart according to claim 4.

6. In a side view of the telescopic mechanism, The auxiliary wheel device is attached to the vehicle body so that, when the telescopic mechanism is in the most retracted state, an angle between a horizontal plane on which the wheels of the hand truck are in contact with the ground and a central axis of the telescopic mechanism becomes an acute angle at the rear side of the hand truck.

5. A cart according to claim 4.

7. The wheels are driven by electricity.

5. A cart according to claim 4.

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