JP3430408B2 - Jack for Shoring - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jack for upsetting a digging groove in a civil engineering construction work, a cross beam material, a sheet pile, or the like, or when constructing a reinforced concrete house or a lightweight steel house. The present invention relates to a support jack used as a jack for temporarily holding a beam such as a steel frame of an upper floor, a horizontal rail of a temporary frame, or a horizontal flap material of a concrete formwork.

[0002]

2. Description of the Related Art Conventionally, a jack of this type has a gear box at one end thereof, and by rotating a driving bevel gear in the gear box, a screw bolt is rotated through the driven bevel gear and screwed to the screw bolt. It has a structure in which the slide tube is extended by moving the mating moving member in the axial direction. Further, in order to reduce the weight of the jack body, the gear box is usually made of an aluminum material, and the bevel gear is made of stainless steel having excellent wear resistance.

[0003]

In the type in which the slide tube is expanded and contracted by the rotation of the screw bolt, the pressure applied to the slide tube when the jack is used is applied to the bevel gear in the gear box via the screw bolt. . At this time, conventionally, the driving bevel gear is cantilevered at one end of the shaft by a gear box, so that when a large load is applied, the free end of the driving bevel gear swings and the bearing portion of the shaft is supported. Also, there is a disadvantage that the gear meshing portion is adversely affected and the transmission efficiency is significantly deteriorated.

Further, in order to reduce the load applied to the bearing surface of the driven bevel gear, conventionally, two steel washers and one synthetic resin washer are combined, and the synthetic resin washer serves as the receiving surface of the gear box. The driven bevel gears are arranged so as to be in contact with each other. However, since the friction coefficient of the synthetic resin washer and the aluminum gearbox and steel washer that contact both sides is significantly different, the resin washer contact is more difficult than the steel washer and the contact surface between the steel washer and the bevel gear seat surface. The surface slides well, so that the contact surface of the resin washer is polished and mirror-like during repeated use. This mirror-like phenomenon is effective in terms of slidability, but the pressure applied to the slide pipe during use of the jack causes a reverse phenomenon of the screw bolt, which causes the pressing force of the jack to be attenuated.

Further, there is a problem that the spiral lead angle of the screw bolt should be taken into consideration. If the spiral lead angle of the screw bolt is large, the movement of the moving member due to rotation will be quick and the expansion and contraction operation of the slide tube can be performed quickly, but the rotation torque becomes large and a large force is required, and the jack is in use. In addition, the axial push-back pressure applied to the slide tube may cause a reverse rotation phenomenon in the screw bolt and the spiral portion. On the contrary, if the spiral lead angle is made smaller, the reverse rotation phenomenon of the screw bolt does not occur, but there is a problem that the expansion and contraction operation of the slide tube due to the rotation of the screw bolt becomes slow and the operability at the site deteriorates.

Therefore, the present invention mainly provides a jack for supporting work in which shaft wobbling of the driving bevel gear is prevented in advance when a load is applied by simply modifying the conventional structure without using any additional member. To aim.

Further, according to the present invention, consideration is given to the material of the washer arranged on the seat surface of the driven bevel gear to prevent the occurrence of the above-mentioned mirroring phenomenon on the washer contact surface, and at the same time, by the inventor. The purpose of the present invention is to provide a jack for supporting work which is excellent in operability and effectiveness by setting the spiral lead angle of the screw bolt based on the test data.

[0008]

In order to achieve the object, the present invention takes the following technical means. That is, in the supporting jack according to the present invention, the movement is prevented in the outer cylinder 1 by rotating the outer cylinder 1 having the gear box 3 at one end and the bevel gear in the gear box 3. Screw bolt 4 that rotates in a fixed state, a moving member 5 that is screwed onto the screw bolt 4 and that moves in the axial direction in the outer cylinder 1 by the rotation of the screw bolt 4, and the moving member 5
A bevel gear in the gear box 3 coaxially with a screw bolt 4 and a slide pipe 2 which is connected to the one end of the outer pipe 1 and is slidably projected from an opening portion of the outer cylinder 1. Fixed driven bevel gear 10
Is held by the shaft 11a in the gear box 3 in a state orthogonal to the shaft 10a of the driven bevel gear 10, and the shaft 11a
Part of the driving bevel gear 11 is exposed to the outside from the gear box 3 to form a drive operating portion 11b, and the driving bevel gear 11 is provided on the surface opposite to the surface provided with the shaft 11a. A support shaft 11c coaxial with the axis of the shaft 11a is formed, and the support shaft 11c is the screw bolt 4
The annular groove 4a is provided on the outer peripheral surface of the, or is arranged around the screw bolt 4 and is rotatably inserted into the hole 16a of the cylindrical cover 16 fixed to the gear box 3. As a result, the driving bevel gear 11 is stably held in a two-sided manner by the shaft 11a at both ends and the support shaft 11c, and can smoothly rotate even under a large load. Also, the support shaft 11c of the driven bevel gear
Is an annular groove 4a formed in the screw bolt 4 or a hole 16 of a cylindrical cover 16 that is conventionally attached.
Since it is inserted into and held in a, it can be simply constructed without requiring any additional member.

[0009]

Further, in the present invention, in addition to the above construction, three washers 7, 8, 9 are mounted between the bearing surface of the driven bevel gear 10 and the receiving surface of the gear box 3, and these three washers are mounted. Among the washers, the washer 7 and the intermediate washer 8 that contact the bearing surface of the driven bevel gear 10 are made of steel material, and the washer 9 that contacts the receiving surface of the gear box 3 is made of stainless steel. The inner diameter of the washer 9 made of steel is formed larger than the outer diameter of the shaft 10a of the driven bevel gear 10, and the outer peripheral surface of the washer 9 is held in contact with the inner surface of the gear box 3, whereby the inner surface of the washer 9 is held. A predetermined gap L is formed, and the shaft 1 of the driven bevel gear 10 is further formed.
0a and the inner peripheral surface of the receiving hole 3a of the gear box 3, a synthetic resin bearing collar 18 is interposed, and the spiral lead angle α of the screw bolt 4 is 11 degrees to 13 degrees. It is also characterized by a structure formed within a range of degrees.

The spiral lead angle α of the screw bolt 4
Is effective within the range of 11 to 13 degrees, but is preferably 12.3 degrees. The stainless steel used as the material for the washer 9 is preferably a ferritic stainless steel that does not undergo transformation and is hardened.

The slide tube 2 and the outer cylinder 1 are configured so that only the slide can be permitted while the relative rotation is prevented by engaging with each other at the concavo-convex ridge portion along the axial direction.

The moving member 5 is assembled so as to be substantially adjacent to the gear box 3 when the slide tube 2 is pushed into the outer cylinder 1 to the maximum, that is, at the maximum contraction as shown in FIG. There is. Therefore, by rotating the bevel gear in the gear box 3 to rotate the screw bolt 4 in the screw advancing direction, the moving member 5 moves leftward in the figure along the screw bolt 4 to extend the slide tube 2. Can be made.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show an embodiment of a jack according to the present invention, in which reference numeral 1 denotes an outer cylinder. An aluminum gear box 3 is integrally connected to one end of the outer cylinder 1.

The gear box 3 has a driving bevel gear 1 in which a rotation axis direction is oriented in a direction orthogonal to an axis of the outer cylinder 1.
1 and a driven bevel gear 10 that meshes with the driving bevel gear 11 with the axis of rotation being the same as the axis of the outer cylinder 1.
The shaft 10a of the driven bevel gear 10 has a receiving hole 3 of the gear box 3.
It is supported by a. Further, the driving bevel gear 11 is held by the shaft 11a in the gear box 3 in a state where its axis is orthogonal to the shaft 10a of the driven bevel gear 10, and a part of the shaft 11a is exposed from the gear box 3 to the outside for driving operation. Part 11b
Is formed. Further, the driving bevel gear 11 is provided with a support shaft 11c coaxial with the axis of the shaft 11a on the surface opposite to the surface provided with the shaft 11a.
Is an annular groove 4 provided on the outer peripheral surface of the screw bolt 4.
It is rotatably fitted and held in a. In this embodiment, a tubular cover 16 is arranged around the screw bolt 4 and fixed to the gear box 3.
The support shaft 11c is fitted into the groove 4a by penetrating the hole 16a formed in the groove 4a. The bevel gears 10 and 11 are made of stainless steel in order to maintain strength and wear resistance.

Further, in this embodiment, three washers 7 are provided between the bearing surface of the driven bevel gear 10 and the receiving surface of the gear box 3.
8 and 9 are attached. Of these three washers, the washer 7 and the intermediate washer 8 that come into contact with the bearing surface of the driven bevel gear 10 are made of steel material, and the washer 9 that comes into contact with the receiving surface of the gear box 3 is made of stainless steel.

The stainless washer 9 has an inner diameter larger than the outer diameter of the shaft 10a of the driven bevel gear 10, and the outer peripheral surface of the washer 9 is supported in contact with the inner surface of the gear box 3. . As a result, a predetermined gap L is maintained between the inner surface of the washer 9 and the outer peripheral surface of the shaft 10a of the driven bevel gear 10. Further, a bearing collar 18 made of synthetic resin is interposed between the outer peripheral surface of the shaft 10a of the driven bevel gear 10 and the inner peripheral surface of the receiving hole 3a of the gear box 3. As the steel material of the washers 7 and 8, JIS symbol S is used.
The rolled steel for general structure of S41 is preferable, and as the stainless steel of the washer 9, a non-quenched ferritic stainless steel with JIS code SUS304 is preferable.

An elongated screw bolt 4 having a length substantially the same as that of the outer cylinder 1 is coaxially connected and fixed to the driven bevel gear 10 by a fixing screw 6 and arranged at the shaft core portion of the outer cylinder 1. A moving member 5 is screwed onto the screw bolt 4, and one end of the slide tube 2 is connected and fixed to the moving member 5. The tip of the slide tube 2 is slidably projected from the tip opening of the outer cylinder 1, and the base plate 12 is fixed to the tip.

As shown in FIG. 3, the slide tube 2 and the outer cylinder 1 are engaged with each other at the ridges and valleys along the axial direction so that only the slide can be permitted while the relative rotation is prevented. Has been done. As a result, the moving member 5 is rotated by rotating the screw bolt 4 in the screwing direction.
Has a structure in which the slide tube 2 can be extended by moving leftward in the drawing along the screw bolt 4. Further, in this embodiment, the spiral lead angle α of the screw bolt 4 is formed to be 12.3 degrees. As a result of repeated tests conducted by the inventor, this lead angle of 12.3 degrees ensures that the reverse rotation of the screw bolt due to the reaction force when the jack is used is reliably prevented, and the moving member 5 is screwed at a proper rotation speed. It was proved that it could be done. However, the spiral lead angle can be effectively implemented even within the range of 11 degrees to 13 degrees.

A stopper 17 for preventing the moving member 5 from being pulled out is provided at the tip of the screw bolt 4, and a base plate 12 symmetrical to the base plate 12 provided at the tip of the slide tube 2 is provided at the outer end of the gear box 3. 'Is provided. In the figure, reference numeral 15 is a carrying handle, and 16 is a sleeve arranged between the screw bolt 4 and the gear box 3.

The jack constructed as described above is used, for example, as shown in FIG. 4, to stab and support the abdominal risers 14, 14 for holding the sheet piles 13, 13 on the left and right sides of the digging groove in civil engineering work. . A handle (not shown) is provided on the drive operation portion 11b exposed to the outside of the gear box 3.
Is detachably attached and the slide tube 2 is used by expanding or contracting by rotating manually or electrically. In addition to the above, as a jack for temporarily holding beams such as steel frames of upper floors, horizontal frames of temporary frames or horizontal flaps of concrete formwork when constructing reinforced concrete houses and lightweight steel houses Can be used. In this case, the outer surfaces of the base plates 12 and 12 'at both ends of the jack are preferably flat surfaces.

When using the above jack, the driving bevel gear 11
Is stably supported by the shafts 11a on both ends and the support shaft 11c in a two-sided manner, so that it can smoothly rotate even when a large load is applied without causing shaft runout. Further, since the washer 7 in contact with the bearing surface of the driven bevel gear 10 and the intermediate washer 8 are made of steel material and the washer 9 in contact with the receiving surface of the gear box 3 is made of stainless steel, the driven bevel gear 10 and the washer 8 are formed. 7, the contact surface between the washer 9 and the receiving surface of the gear box 3, and the contact surface between the washers 7, 8 and 9 are extremely different from each other like a resin because of the metal-to-metal contact. Therefore, the respective contact surfaces of the washer do not slip on average and the mirroring phenomenon and the burning phenomenon do not occur in part. Further, since the predetermined gap L is held on the inner surface of the stainless steel washer 9, it is possible to reliably prevent the baking due to the sliding contact between the stainless steel materials. In addition, driven bevel gear 1
Since the bearing collar 18 made of synthetic resin is interposed between the outer peripheral surface of the shaft 10a of 0 and the inner peripheral surface of the receiving hole 3a of the gear box 3, the shaft 10a can be smoothly rotated with respect to the receiving hole 3a. be able to.

At the same time, by setting the spiral lead angle of the screw bolt to 12.3 degrees, the reverse rotation of the screw bolt due to the reaction force when the jack is used can be surely prevented.
Moreover, the moving member 5 can be screwed at an appropriate rotation speed, and good workability on site can be maintained.

In the above embodiment, the support shaft 11c of the driving bevel gear 11 penetrates the hole 16a of the cylindrical cover 16 and is inserted and retained in the annular groove 4a provided on the outer peripheral surface of the screw bolt 4. However, as shown in FIG. 5, the support shaft 11c may be inserted and held only in the hole 16a of the tubular cover 16. It is also possible to omit the tubular cover 16 in the embodiment shown in FIGS.

Although the representative embodiments of the present invention have been described above, the present invention is not necessarily limited to the structures of the above-mentioned embodiments, and is appropriately modified within the scope of having the constituent requirements and effects. Of course, it can be implemented.

[0025]

Since the jack of the present invention is constructed as described above, the driving bevel gear is stably held in a two-sided manner by the shafts at both ends, so that it can swing even under a large load. It can rotate smoothly without. Further, it is possible to prevent the washer arranged on the bearing surface of the driven bevel gear from being mirror-finished or seized and to maintain smooth rotation for a long period of time. In addition, by setting the spiral lead angle of the screw bolt to a predetermined angle, it is possible to reliably prevent the reverse rotation phenomenon of the screw bolt due to the reaction force when the jack is used while maintaining an appropriate rotational operability. In addition, there is a remarkable effect that it is possible to provide a jack for supporting work which is excellent in operability and effectiveness.

[Brief description of drawings]

FIG. 1 is an overall transverse sectional view showing an embodiment of a jack according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of the jack.

FIG. 3 is an enlarged cross-sectional view taken along the line AA in FIG.

FIG. 4 is an explanatory view showing an example of use of the jack according to the present invention.

FIG. 5 shows another embodiment of the jack according to the present invention.
Similar sectional drawing.

[Explanation of symbols]

1 outer cylinder 2 slide tubes 3 gearbox 4 screw bolts 4a Screw bolt groove 5 Moving member 7,8,9 washers 10 driven bevel gears 10a Shaft of driven bevel gear 11 Driving Bevel Gear 11a Driving bevel gear shaft 11b Drive operation unit 11c Driving bevel gear support shaft 16 tubular cover 16a Hole in cylindrical cover 18 Bearing collar L gap α spiral lead angle

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) E02D 17/08 B66F 19/00 F16H 1/14 B66F 3/08 B66F 3/18

Claims (3)

(57) [Claims] 1. An outer cylinder (1) having a gear box (3) at one end.
A screw bolt (4) that rotates in a state in which movement in the outer cylinder (1) is blocked by rotating a bevel gear in the gear box (3), and the screw bolt (4) A moving member (5) which is screwed and moves axially in the outer cylinder (1) by rotation of the screw bolt (4), and one end of which is connected to the moving member (5) and which has the outer cylinder (1). ) Is a jack consisting of a slide tube (2) slidably projecting from the opening of the tip end of the gearbox (3), and the bevel gear in the gearbox (3) is coaxially fixed to the screw bolt (4). Bevel Gear (10)
And the shaft (11a) is held by the gear box (3) in a state orthogonal to the shaft (10a) of the driven bevel gear (10), and the shaft (11a)
A part of the driving bevel gear (11) which is exposed to the outside from the gear box (3) and forms the drive operating part (11b), and the shaft (11a) of the driving bevel gear (11) is provided. A support shaft (11c) coaxial with the shaft core of the shaft (11a) is formed on the surface opposite to the surface where the support shaft (11c) is the screw bolt (4).
It is rotatable in the annular groove (4a) provided on the outer peripheral surface of the cylinder or in the hole (16a) of the tubular cover (16) that is arranged around the screw bolt (4) and fixed to the gear box (3). The support jack inserted in the. 2. Three washers (7), (8), (9) are mounted between the bearing surface of the driven bevel gear (10) and the receiving surface of the gear box (3), and these three Out of the washers, driven bevel gears (10)
The washer (7) in contact with the seat surface and the intermediate washer (8) are made of steel material, and the washer (9) in contact with the receiving surface of the gear box (3) is made of stainless steel. The inner diameter of the washer (9) is formed larger than the outer diameter of the shaft (10a) of the driven bevel gear (10), and the outer peripheral surface of the washer (9) is held in contact with the inner surface of the gear box (3). As a result, a predetermined gap (L) is formed on the inner surface of the washer (9), and further the outer peripheral surface of the shaft (10a) of the driven bevel gear (10) and the receiving hole (3a) of the gear box (3) are formed. The jack for supporting work according to claim 1, wherein a bearing collar (18) made of synthetic resin is interposed between the jack and the inner peripheral surface. 3. The jack for supporting work according to claim 1, wherein the spiral lead angle (α) of the screw bolt (4) is formed within a range of 11 degrees to 13 degrees.