JP2016147724A - Screw jack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screw jack which, firstly, can jack up efficiently, and secondly, can make a bed within a maximum width while ensuring a minimum grounding area of the bed.SOLUTION: A case 13 comprises a case body part 13a, a cylindrical case part 13b, and a handle joint support cylindrical part 13c. As shown in Fig. 5(a), (b) and Fig. 6(a), (b), the case body part 13a comprises an inverted cup part 13a2 having an inverted cup shape. On a joint surface 13a3 joining the case body part 13a and the handle joint support cylindrical part 13c in the inverted cup part 13a2, a handle joint through hole 13a4 for inserting a tip part of a handle joint 17 therethrough is formed. The joint surface 13a3 is formed of a flat surface.SELECTED DRAWING: Figure 5

Description

  The present invention mainly relates to a three-stage screw jack that is installed in large automobiles, buses, trucks, and the like and is used to lift a vehicle when changing tires.

  As a screw jack, for example, a cylindrical case projecting on a base, an outer cylinder (ram guide) that is slidably fitted in the axial direction inside the case, and an inner side of the outer cylinder A three-stage screw jack having an inner cylinder (ram) that is slidably fitted in a vertical direction is known (see, for example, Patent Document 1).

  When this three-stage screw jack is used, for example, a part of an automobile or the like is loaded on a vehicle receiving portion that is rotatably attached to the upper end of a ram (inner cylinder) with bolts or screws, and a handle is attached. When rotated, the small bevel gear, the large and small bevel gears, and the large bevel gear are rotated, the main screw shaft is rotated to raise the outer cylinder, and the inner cylinder that is screwed with the outer cylinder is raised.

  When the inner cylinder (ram) rises, the outer cylinder (ram guide) is also pulled up by the inner cylinder and rises until it hits the stopper pin provided on the upper part of the main screw shaft and the inner screw of the outer cylinder, and the inner cylinder (ram) A vehicle or the like is lifted through a vehicle receiving portion provided at the upper end.

Registered Utility Model No. 3046162

  However, in the conventional screw jack described in Patent Document 1, the case main body portion of the case has a hemispherical shape as if the bowl is inverted, and thus is provided at the tip of the handle joint supported by the cylindrical case portion. Further, there is a problem that the diameter of the small bevel gear cannot be ensured large, the number of teeth of the small bevel gear is reduced, and the rotation speed of the handle is increased correspondingly, resulting in inefficiency when jacking up.

  In addition, since such screw jacks are used to lift heavy vehicles such as large cars and buses, a large load is applied to the bed to which the case is fixed, and there is a risk of falling down. Requires a minimum bed surface area or ground contact area.

  On the other hand, most of such screw jacks are housed in a vehicle trunk box, which limits the maximum width of the bed.

  Therefore, the present invention has been made paying attention to such a problem. First, it is possible to jack up efficiently, and secondly, while ensuring the minimum ground contact area of the bed, An object is to provide a screw jack within the maximum width.

In order to solve the first problem, a first feature of the screw jack of the present invention is that a case is mounted on a bed provided with a thrust bearing in the center, and a screw is formed on the outer peripheral surface of the thrust bearing. A large bevel gear is provided with an upright main screw shaft provided with a stopper pin at the upper end. The large bevel gear meshes with a small bevel gear that rotates by driving from the outside of the case. The main screw outer peripheral screw portion provided on the outer peripheral surface of the main screw shaft rotating via the gear meshes with the auxiliary screw inner peripheral screw portion provided on the inner surface of the lower portion of the auxiliary screw cylinder, while the auxiliary screw cylinder outer periphery The auxiliary screw outer peripheral screw portion provided on the surface meshes with the inner cylinder inner peripheral screw portion provided on the inner peripheral surface of the lower portion of the inner cylinder, and the large bevel gear and the main screw shaft are rotated by the rotation of the small bevel gear. And the auxiliary screw cylinder is rotated by the rotation of the main screw shaft. While moving up and down, the inner cylinder is moved up and down by rotation of the auxiliary screw cylinder, and an outer cylinder side provided with an inner cylinder side stopper provided on the outer peripheral surface side of the lower part of the inner cylinder on the inner peripheral surface side of the upper part of the outer cylinder A screw jack provided with a receiving part for receiving a vehicle or the like on the upper part of the inner cylinder by raising the outer cylinder by coming into contact with the stopper, and the case is a bowl fixed on the bed. A reverse cup-shaped case main body that is inverted, and a predetermined length extending in a vertical direction from an upper portion of the case main body, the inner cylinder, the outer cylinder, the main screw shaft, and the auxiliary screw cylinder And a handle joint support cylindrical portion in which a handle joint is inserted and rotatably supports the handle joint, and the case main body portion and the handle joint support cylindrical portion are joined to each other. Case book The bonding surface of the parts which is formed of the flat surface.
In order to solve the second problem, a second feature of the screw jack of the present invention is that, in the above-described screw jack, the bed has four corners of a square having a width of approximately 109 mm, and the center of the bed. An approximate octagon that is more eccentric and approximates an octagon having four straight edges and a curved edge cut by an arc of radius approximately half the length of the diagonal of the square; and The distance between the curved edges facing each other across the center of the bed is approximately 120 mm or more.

According to the first feature of the screw jack of the present invention, since the joining surface of the case body portion where the case body portion and the handle joint support cylindrical portion are joined is a flat surface, the joining surface is flatter than the curved surface. Thus, the outer diameter of the small bevel gear can be increased, and jacking up can be efficiently performed by increasing the number of teeth of the small bevel gear.
Further, according to a second feature of the screw jack of the present invention, in the above-described screw jack, the bed has four corners of a square having a width of approximately 109 mm that are eccentric from the center of the bed, respectively, A curved edge that is an approximate octagon that approximates an octagon having four straight edges and a curved edge cut by a circular arc having a radius approximately half the length of the diagonal line, and that is opposed to the center of the bed. Because the distance between the parts is almost 120 mm or more, the maximum width of the bed is 109 mm at the maximum, which is the in-vehicle requirement in the trunk, while satisfying the minimum bed area standards such as Australia and New Zealand that are not satisfied by the 109 mm diameter circle Can be suppressed within.

It is sectional drawing which shows the cross-section of the contracted state (accommodated state) which is not using the screw jack of embodiment which concerns on this invention. It is an end view which shows the AA line cross section in FIG. It is a top view of the screw jack of the embodiment concerning the present invention. (A)-(c) It is a top view of a bed which constitutes a screw jack of an embodiment concerning the present invention, a front view, and a BB line sectional view, respectively. (A), (b) It is the top view and front view of a case main body which respectively comprise the screw jack of embodiment which concerns on this invention. (A), (b) is the right view of the case main body which comprises the screw jack of embodiment which concerns on this invention, respectively, and CC sectional view. (A), (b) Front view, left side view of the handle joint and the small bevel gear provided at its tip when the outer diameter of the small bevel gear constituting the screw jack of the embodiment according to the present invention is small, FIGS. 4A and 4B are a front view and a left side view of a handle joint and a small bevel gear provided at the tip of the small bevel gear constituting the screw jack according to the embodiment of the present invention, respectively. FIG. It is a perspective view of the inner cylinder which comprises the screw jack of embodiment which concerns on this invention. (A)-(c) It is a top view, a front view, and a side view of an inner cylinder which constitutes a screw jack of an embodiment concerning the present invention, respectively. (A), (b) is the DD sectional view taken on the line in FIG.9 (b), respectively, and the EE sectional view taken on the line. It is a perspective view of the outer cylinder which comprises the screw jack of embodiment which concerns on this invention. (A)-(c) It is a top view, a front view, and a left side view of an outer cylinder which constitutes a screw jack of an embodiment concerning the present invention, respectively. (A), (b) is the FF sectional view taken on the line in FIG.12 (c), respectively, and the GG sectional view taken on the line in FIG.12 (b). It is front sectional drawing which shows the cross-section when the outer cylinder and auxiliary screw cylinder which are the 2nd step | paragraph of the screw jack of embodiment which concerns on this invention have fully extended upwards from the 1st step | paragraph cylindrical case part. It is right side sectional drawing which shows the cross-section when the outer cylinder and auxiliary screw cylinder which are the 2nd step | paragraph of the screw jack of embodiment which concerns on this invention have fully extended upwards from the 1st step | paragraph cylindrical case part. . It is the HH line | wire end view in FIG. It is a front view which shows the state which the inner cylinder which is the 3rd step | paragraph of the screw jack of embodiment which concerns on this invention, the outer cylinder which is the 2nd step | paragraph, etc. extended all the way up from the 1st step | paragraph cylindrical case part. . FIG. 3 is a left side view showing a state in which an inner cylinder as a third stage and an outer cylinder as a second stage of the screw jack according to the embodiment of the present invention extend as far as possible upward from the first-stage cylindrical case portion. is there. The front which shows the section structure when the inner cylinder which is the 3rd step of the screw jack of the embodiment concerning the present invention, the outer tube which is the 2nd step, etc. extends all the way up from the cylindrical case part of the 1st step. It is sectional drawing. It is the II sectional view taken on the line in FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a screw jack according to the present invention will be described in detail with reference to the accompanying drawings.

Embodiment.
As shown in FIGS. 1-3, the screw jack 1 of embodiment which concerns on this invention is comprised by attaching the case 13 on the bed 12 which provided the thrust bearing 11 in the center.

<Composition of bed 12>
The bed 12 is configured as shown in FIGS. 4A to 4C, and four square corners having a width W1 of approximately 109 mm are eccentric from the center 12d of the bed 12, respectively. And an approximate octagon that approximates an octagon having four straight edge portions 12b and a curved edge portion 12c cut by an arc having a radius r (approximately 77 mm) that is approximately half the length of the diagonal line, An interval W2 between the curved edge portions 12c and 12c facing each other across the center 12d of the bed 12 is approximately 120 mm.

  Therefore, according to the screw jack 1 of this embodiment, since the surface area of the bed 12 in plan view is larger than the area of a circle with a diameter of 109 mm, the minimum of the bed 12 such as Australia or New Zealand that is not satisfied with a circle with a diameter of 109 mm. While satisfying the standard of the area, the width W1 of the bed 12 is approximately 109 mm, so that the width required by the vehicle in the trunk can be suppressed within the maximum width of the bed 12 of 109 mm.

  The bed 12 is provided with a bolt hole 12e for inserting a bolt 12a1 for fixing the case 13 and a recess 12f for providing the thrust bearing 11.

<Configuration of case 13>
As shown in FIGS. 1 to 3, the case 13 includes a case main body 13 a that is fixed on the bed 12 in an inverted cup shape that reverses the bowl that is fixed on the bed 12 by bolts and nuts 12 a, A first-stage cylindrical case portion 13b having a predetermined length extending in the vertical direction from the upper portion of the case body 13a and a handle joint 17 to be described later are inserted, and a handle joint support cylinder that rotatably supports the handle joint 17 is inserted. Part 13c.

  As shown in FIGS. 5 (a) and 5 (b) and FIGS. 6 (a) and 6 (b), the case body 13a has an inverted cup shape in which the bowl is inverted, and has a flat flange portion (base portion). ) 13a1 and a reverse cup-shaped reverse cup portion 13a2, and the joint surface 13a3 joining the case main body portion 13a and the handle joint support cylindrical portion 13c in the reverse cup portion 13a2 is provided at the tip of the handle joint 17 A through hole 13a4 for a handle joint for passing the part is formed, and the joint surface 13a3 is formed by a plane.

  Therefore, by forming the joint surface 13a3 as a flat surface, the outer diameter of the small bevel gear 18 provided at the distal end portion of the handle joint 17 passing through the handle joint through hole 13a4 and provided along the inner surface of the joint surface 13a3 is reduced. It becomes possible to enlarge, and the number of teeth of the small bevel gear 18 can be increased.

  7A to 7E show the relationship between the outer diameter of the small bevel gear 18 provided at the tip of the handle joint 17 and the number of teeth of the small bevel gear 18.

  7 (a) and 7 (b) show the case where the outer diameter of the small bevel gear 18 is small and the number of teeth of the small bevel gear 18 is 10, whereas FIGS. 7 (c) and (d) Shows the case where the outer diameter of the small bevel gear 18 is large and the number of teeth of the small bevel gear 18 is twelve. Even if the outer diameter of the handle joint 17 is the same, the outer diameter of the small bevel gear 18 is increased. This shows that the number of teeth of the small bevel gear 18 increases.

  As a result, according to the screw jack 1 of the present embodiment, the joining surface 13a3 that joins the case body portion 13a and the handle joint support cylindrical portion 13c is configured as a flat surface, so that the outer diameter of the small bevel gear 18 is increased. The number of teeth of the small bevel gear 18 can be increased, and jacking up can be efficiently performed.

  As shown in FIGS. 5 (a) and 5 (b) and FIGS. 6 (a) and 6 (b), a cylindrical case portion 13b is joined to the upper portion of the case body portion 13a by welding or the like. A main portion through-hole 13a5 for passing the inner cylinder 20, the outer cylinder 21, the main screw shaft 15, and the auxiliary screw cylinder 19 through the case body 13a and the cylindrical case 13b is provided.

  Further, in the case main body 13a, a large bevel gear 14 is rotatably provided on the thrust bearing 11, and the outer periphery of the main screw extends from the lower end to the upper end on the outer peripheral surface at the center of the large bevel gear 14. A screw portion 15a is formed, a stopper pin 16 is provided at the upper end portion, and a main screw shaft 15 is erected.

  The large bevel gear 14 meshes with a small bevel gear 18 provided at a tip end portion of the handle joint 17 rotatably supported by the handle joint support cylindrical portion 13c, and when the handle joint 17 is rotated, the small bevel gear 18 is rotated. Is rotated so that the large bevel gear 14 is also rotated. In addition, an insertion hole 17 a into which a screwdriver or a dedicated rod is inserted to rotate the handle joint 17 is provided at the rear end portion of the handle joint 17.

  The main screw outer peripheral screw portion 15a provided on the outer peripheral surface of the main screw shaft 15 is engaged with the auxiliary screw inner peripheral screw portion 19a provided on the inner surface of the lower portion of the auxiliary screw cylinder 19, while The auxiliary screw outer peripheral screw portion 19b provided on the surface is engaged with the inner cylinder inner peripheral screw portion 20a provided on the inner peripheral surface of the lower portion of the inner cylinder 20.

  Here, the main screw shaft 15 and the auxiliary screw cylinder 19 reduce the frictional resistance of the threaded portion by the gas soft nitriding treatment, thereby making it resistant to wear and improving the durability performance. The gas soft nitriding treatment increases the hardness of the load receiving surface of the threaded portion by precipitating a compound layer on the surface, thereby improving the wear resistance.

  Further, the material of the main screw shaft 15 and the auxiliary screw cylinder 19 is FCD400 (spheroidal graphite cast iron), so that the toughness is improved and the fracture resistance against lateral load is improved.

  This is a high safety risk because FC200 (gray cast iron) is a fracture mode that breaks when a lateral folding test is performed on a brittle material peculiar to castings. For this reason, steel may be used for the main screw shaft 15 and the auxiliary screw cylinder 19 to take measures against this damage mode. However, steel is too viscous to deteriorate the machinability and reduce the mass productivity in machining. In addition, when steel is used, a technique called plastic working (rolling) is used to solve the problem, but this requires a large amount of capital investment and costs. The toughness of FCD400 (spheroidal graphite cast iron) is a material having intermediate toughness between FC200 (grey cast iron) and steel, and is a material that can be cut relatively easily. Therefore, in the screw jack 1 of this embodiment, It was used as a material for the screw shaft 15 and the auxiliary screw cylinder 19.

  As shown in FIG. 1 and the like, the cylindrical case portion 13b has a predetermined length of steel pipe that houses the main screw shaft 15, the auxiliary screw cylinder 19, the inner cylinder 20, and the outer cylinder 21 when the screw jack 1 is not used. As shown in FIG. 2 and the like, the main guide groove portion 13b1 extending in the vertical direction for guiding the guide portion 21a of the outer cylinder 21 described later in the vertical direction and the side facing the main guide groove portion 13b1, that is, On the opposite side of 180 degrees, there is a sub guide groove 13b2 extending in the vertical direction that guides the retaining projection 21b of the outer cylinder 21 in the vertical direction.

  When the outer cylinder 21 rises, the retaining guide 21b of the outer cylinder 21 comes into contact with the upper portion of the sub guide groove 13b2 so that the outer cylinder 21 does not fall out of the cylindrical case 13b (center 12d). A cylindrical case side stopper portion 13b3 (see FIG. 12 and the like) that is bent toward the side) is provided.

  Further, the inner cylinder side stopper portion 20b provided on the outer peripheral surface side of the lower portion of the inner cylinder 20 abuts on the outer cylinder side stopper portion 21c provided on the inner peripheral surface side of the upper portion of the outer cylinder 21, so The cylinder 21 is also configured to be raised.

  That is, in the screw jack 1, the large bevel gear 14 and the main screw shaft 15 are rotated by the rotation of the handle joint 17 and the small bevel gear 18, and the auxiliary screw cylinder 19 is moved up and down by the rotation of the main screw shaft 15, while the auxiliary screw When the inner cylinder 20 is moved up and down by the rotation of the cylinder 19, the inner cylinder side stopper portion 20 b provided on the outer peripheral surface side of the lower portion of the inner cylinder 20 is changed to the outer cylinder side stopper portion 21 c provided on the inner peripheral surface side of the upper portion of the outer cylinder 21. The outer cylinder 21 is also lifted by contact.

  A vehicle receiving portion 22 that receives the load of a vehicle such as a large automobile, a bus, or a truck is attached to the upper portion of the inner cylinder 20.

<Configuration of inner cylinder 20>
FIG. 8 is a perspective view showing the appearance of the inner cylinder 20 constituting the screw jack 1 of the embodiment, and FIGS. 9A to 9C are a plan view, a front view, a right side view, and FIG. (A), (b) is the BB sectional view taken on the line in FIG.9 (b), (c), respectively, and CC sectional view taken on the line.

  The inner cylinder 20 is not made of steel (steel material), but is made of FCD400 (spherical graphite cast iron) that has been subjected to gas soft nitriding, like the main screw shaft 15 and the auxiliary screw cylinder 19, and has an inner peripheral surface as described above. The inner cylinder inner peripheral thread portion 20a is provided on the side, while the inner cylinder 20 has a circular cut surface when the inner cylinder 20 is cut in a horizontal direction perpendicular to the longitudinal direction below the outer surface. A side stopper portion 20b is provided.

  As shown in FIGS. 8 to 10 and the like, the outer surface of the inner cylinder 20 other than the lower inner cylinder-side stopper portion 20b has six outer circumferential surfaces of the inner cylinder 20 at predetermined intervals. The inner cylinder slide portion 20c in which the six long flat side surfaces 20c1 and the curved side surface 20c2 are alternately arranged is formed by cutting in a plane, and the inner cylinder slide portion 20c is in a horizontal direction perpendicular to the longitudinal direction. The cut surface shape at the time of cutting into six is the six long curved side surfaces 20c2 provided alternately with the six long flat side surfaces 20c1 and the long curved side surfaces 20c2 by cutting off a circle with six straight lines at predetermined intervals. It is an approximate hexagon as a corner, and the long flat side surface 20c1 at that portion is a portion recessed from the outer peripheral surface of the inner cylinder side stopper portion 20b.

  Therefore, in the inner cylinder 20, the long curved side surface 20c2 of the inner cylinder slide portion 20c and the surface of the inner cylinder side stopper portion 20b are continuously flush with each other as shown in FIGS. The long flat side surface 20c1 of the inner cylinder slide portion 20c and the inner cylinder side stopper portion 20b have a step, and the long flat side surface 20c1 of the inner cylinder slide portion 20c is recessed inward than the inner cylinder side stopper portion 20b. It will be.

  In addition, in the upper part of the outer surface of the inner cylinder 20, that is, the upper part of the outer surface of the inner cylinder slide part 20c, as shown in FIG. A C-ring housing groove 20d for housing the C-ring 23 that fits in is formed, and as shown in FIG. 14B, the C-ring housing groove 20d accommodates the elastic C-ring 23. .

<Configuration of outer cylinder 21>
11 is a perspective view showing an external appearance of the outer cylinder 21 constituting the screw jack 1 of the embodiment, and FIGS. 12A to 12C are a front view, a right side view, a plan view, and FIG. 13 of the outer cylinder 21, respectively. (A), (b) is the BB sectional view taken on the line in FIG.12 (b), (c), respectively, and CC sectional view taken on the line.

  The outer cylinder 21 is made of a steel pipe, and as shown in FIGS. 11 to 13, the inner cylinder 20 has an inner diameter corresponding to the circular shape of the cut surface shape of the inner cylinder side stopper portion 20 b so that it can be accommodated when the inner cylinder 20 is lowered. The outer peripheral surface of the guide portion 21a protrudes from the inner side to the outer side with a predetermined width from the upper end portion to the lower end portion, and is guided by a main guide groove portion 13b1 of a case body portion 13b of the case 13 described later. Is provided.

  Further, on the opposite side of the outer peripheral surface of the outer cylinder 21 from the lower part of the guide portion 21a, as shown in FIGS. 11 to 13, the outer cylinder 21 is outside from the inside so as not to come out of the case main body portion 13a of the case 13. A retaining protrusion 21b that protrudes toward the surface is provided.

  Moreover, as shown in FIGS. 11-13, only the upper part of the outer cylinder 21, only the cut surface shape of the inner cylinder side slide part 20c of the inner cylinder 20, that is, the outer shape of the six long flat side surfaces 20c1 and the long curved side surface 20c2. The outer cylinder side stopper part 21c which has the shape crushed toward the inner side from the outer side is provided so that it may become the approximate hexagon which a line draws.

  The outer cylinder-side stopper portion 21c at the top of the outer cylinder 21 has six short flat side surfaces 21c1 and a long curved side surface by linearly crushing the upper end portion of the cylindrical outer cylinder 20 at six locations at predetermined intervals from the outside to the inside. 21c2 and the alternating shape are formed.

  Next, the operation and effect of the screw jack 1 of the present embodiment configured as described above will be described.

  First, the screw jack 1 according to the embodiment in a contracted state is moved under a vehicle (not shown) to be jacked up, and the bottom side of the bed 12 touches the ground as shown in FIG.

  Then, in the screw jack 1 of this embodiment, as shown in FIG. 4, since the surface area of the bed 12 in plan view is larger than the area of a circle with a diameter of 109 mm, Australia, New Zealand, etc. that are not satisfied with a circle with a diameter of 109 mm While the minimum area standard of the bed 12 is satisfied, the width, which is a vehicle-mounted requirement in the trunk, can be suppressed within the maximum width of the bed 12 of 109 mm at the maximum.

  Next, as shown in FIG. 1 and the like, when the insertion hole 17a driver of the handle joint 17 or a dedicated rod is inserted and rotated, the handle joint 17 and the small bevel gear 18 provided at the tip thereof rotate, The large bevel gear 14 meshed with the small bevel gear 18 is rotated.

  Then, in the screw jack 1 of this embodiment, as shown in FIGS. 5 and 6, the joint surface 13a3 that joins the case main body portion 13a and the handle joint support cylindrical portion 13c is configured as a flat surface, so the small bevel gear 18 The outer diameter of the bevel gear 18 can be increased to increase the number of teeth of the small bevel gear 18 and jacking up can be efficiently performed.

  Then, the main screw shaft 15 whose lower end is fixed to the large bevel gear 14 is rotated by the rotation of the large bevel gear 14, and the main screw outer peripheral screw provided on the outer peripheral surface of the main screw shaft 15 as shown in FIG. The auxiliary screw cylinder 19 in which the auxiliary screw inner peripheral screw portion 19a is engaged with the portion 15a is raised.

  The auxiliary screw cylinder 19 rises, and as shown in FIGS. 16 to 18, the upper part of the auxiliary screw inner peripheral screw part 19 a provided on the inner surface of the lower part of the auxiliary screw cylinder 19 is provided on the outer peripheral surface of the main screw shaft 15. When abutting against the stopper pin 16 embedded in the upper part of the main screw outer peripheral screw portion 15 a, the auxiliary screw cylinder 19 is fixed to the main screw shaft 15, and the auxiliary screw cylinder 19 is also rotated by the rotation of the main screw shaft 15. Become.

  When the auxiliary screw cylinder 19 rotates, the auxiliary screw outer peripheral screw part 19b provided on the outer peripheral surface of the auxiliary screw cylinder 19 and the inner cylinder inner peripheral screw part 20a provided on the inner peripheral surface of the lower part of the inner cylinder 20 mesh with each other. Therefore, the inner cylinder 20 is raised.

  When the inner cylinder 20 is raised by the rotation of the auxiliary screw cylinder 19, an inner cylinder-side stopper portion 20 b is provided at the lower portion of the outer surface of the inner cylinder 20, and the inner cylinder-side stopper portion 20 b serves as the outer cylinder 21. When it comes into contact with the upper outer cylinder side stopper portion 21c, the outer cylinder 21 is raised together with the inner cylinder 20.

  Then, the outer cylinder 21 rises together with the inner cylinder 20, and the guide portion 21a and the retaining projection 21b of the outer cylinder 21 are guided to the main guide groove portion 13b1 and the sub guide groove portion 13b2 of the cylindrical case portion 13b, respectively. When the outer cylinder 21 as well as the inner cylinder 20 rises from the cylindrical case portion 13b of the case 13, the retaining projection 21b of the outer cylinder 21 eventually becomes the sub guide groove portion of the cylindrical case portion 13b. As shown in FIGS. 19 to 18, the ascending of the inner cylinder 20 and the outer cylinder 21 is stopped by coming into contact with the cylindrical case side stopper 13 b 3 at the upper part of 13 b 2.

  Therefore, in the screw jack 1 of the present embodiment, the case 13 includes the case main body portion 13a, the cylindrical case portion 13b, and the handle joint support cylindrical portion 13c, and the case main body portion 13a is shown in FIGS. 6 (a) and 6 (b), a reverse cup-shaped reverse cup portion 13a2 is provided, and a joint surface 13a3 for joining the case main body portion 13a and the handle joint support cylindrical portion 13c in the reverse cup portion 13a2 is provided. Since the handle joint through-hole 13a4 for passing the tip end portion of the handle joint 17 is formed and the joint surface 13a3 is formed as a flat surface, the outer diameter of the small bevel gear 18 is increased to increase the teeth of the small bevel gear 18. The number can be increased and jacked up efficiently.

  Further, in the screw jack 1 of the present embodiment, the bed 12 has the four corners of the square having a width W1 of approximately 109 mm eccentric from the center 12d of the bed 12, respectively, and is approximately ½ of the diagonal of the square. And an approximate octagonal shape approximating an octagon having four straight edge portions 12b and a curved edge portion 12c cut out by an arc having a radius r (approximately 77 mm) of length, and sandwiching the center 12d of the bed 12 Since the distance W2 between the curved edge portions 12c, 12c facing each other is approximately 120 mm, the surface area of the bed 12 in plan view is larger than the area of a circle having a diameter of 109 mm.

  As a result, according to the screw jack 1 of the present embodiment, the width W1 of the bed 12 is approximately 109 mm while satisfying the minimum area standard of the bed 12 such as Australia and New Zealand that is not satisfied by the circular shape of 109 mm in diameter. The width, which is a vehicle-mounted requirement in the trunk, can be suppressed within the maximum width of the bed 12 of 109 mm at the maximum.

DESCRIPTION OF SYMBOLS 1 Screw jack 11 Thrust bearing 12 Bed 13 Case 13a Case main-body part 13a1 Flange part (bottom part)
13a2 Reverse cup portion 13a3 Joint surface 13a4 Handle joint through hole 13b Cylindrical case portion 13b1 Main guide groove portion 13b2 Sub guide groove portion 13c Handle joint support cylindrical portion 14 Large bevel gear 15 Main screw shaft 15a Main screw outer peripheral screw portion 16 Stopper pin 17 Handle joint 18 Small bevel gear 19 Auxiliary screw cylinder 19a Auxiliary screw inner peripheral screw part 19b Auxiliary screw outer peripheral screw part 20 Inner cylinder 20a Inner cylinder inner peripheral screw part 20b Inner cylinder side stopper part 20c Inner cylinder slide part 20d C-ring accommodating groove part 21 Outer cylinder 21a Guide portion 21b Retaining protrusion 22 Vehicle receiving portion 22a Upper surface 22b Cylindrical side surface 22c C-ring fitting groove 23 C-ring

Claims (2)

A case is mounted on a bed provided with a thrust bearing in the center, a screw is formed on the outer peripheral surface of the thrust bearing, and a large bevel gear with a main screw shaft provided with a stopper pin at the upper end is made upright. The large bevel gear is meshed with a small bevel gear that rotates by driving from the outside of the case, while the main screw outer peripheral thread portion provided on the outer peripheral surface of the main screw shaft that rotates through the large bevel gear is provided. Is engaged with the inner screw portion of the auxiliary screw provided on the inner surface of the lower portion of the auxiliary screw cylinder, while the outer screw portion of the auxiliary screw provided on the outer peripheral surface of the auxiliary screw tube is provided on the inner peripheral surface of the lower portion of the inner cylinder. The inner cylinder inner peripheral screw part is meshed,
The rotation of the small bevel gear rotates the large bevel gear and the main screw shaft, and the rotation of the main screw shaft raises and lowers the auxiliary screw tube, while the rotation of the auxiliary screw tube raises and lowers the inner tube. The outer cylinder is also raised by the inner cylinder stopper provided on the outer peripheral surface of the lower part of the inner cylinder abutting the stopper on the outer cylinder provided on the inner peripheral surface of the upper part of the outer cylinder. A screw jack provided with a receiving portion for receiving a vehicle or the like at the top,
The case is
An inverted cup-shaped case main body like a bowl fixed on the bed,
A cylindrical cylindrical case portion having a predetermined length extending in the vertical direction from the upper portion of the case body, and housing the inner cylinder, the outer cylinder, the main screw shaft, and the auxiliary screw cylinder,
A handle joint is inserted, and includes a handle joint support cylindrical portion that rotatably supports the handle joint;
The screw jack according to claim 1, wherein a joint surface of the case main body portion where the case main body portion and the handle joint support cylindrical portion are joined is configured as a flat surface. The screw jack according to claim 1,
The bed is
Four straight and curvilinear edges, each of which has four corners of a square with a width of approximately 109 mm, which are eccentric from the center of the bed and cut by an arc having a radius of approximately half the diagonal of the square. An approximate octagon approximating an octagon having a portion,
A screw jack characterized in that the interval between curved edges facing each other across the center of the bed is approximately 120 mm or more.

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