JP2012200473A - Armrest device for construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an armrest device for a construction machine, preventing loosening of a fastener related to fixing of a height position of an armrest, and preventing the armrest from falling even if the fastener loosens due to insufficient tightening or the like of the fastener.SOLUTION: In this armrest device 20 for the construction machine, the height of the armrest 20a on which an elbow is placed is adjustable. The armrest device includes: an inner post 21 supporting the armrest 20a; an outer post 22 vertically movably supporting the inner post 21; the fastener 30 fixing a relative position of the inner post 21 to the outer post 22; loosening prevention means 50 stopping relative movement between the inner post 21 and the outer post 22 to a direction to loosen the fastener 30 to prevent that the fastener 30 loosens; and fall prevention means 55 stopping vertical relative movement of the inner post 21 to the outer post 22 when the fastener 30 is in a loosening state (non-fixed state) to prevent that the armrest 20a falls.

Description

  The present invention relates to an armrest device for a construction machine in which an armrest on which an elbow is placed is configured to be adjustable in height.

  As this type of conventional armrest device, there is one proposed in Patent Document 1, for example.

Japanese Patent Laid-Open No. 10-331199

  As shown in FIG. 17, the armrest device 100 according to Patent Document 1 is attached to the back side of the console box 101. The armrest device 100 includes a support column 103 that supports the armrest 102. The column 103 has a rectangular cross section and has a shape extending in an arc shape in the vertical direction, and is movable in the vertical direction by a cylindrical guide 104 attached to the back surface of the console box 101.

A plurality of semicircular grooves 103a are provided on the back surface of the support column 103 at a predetermined pitch according to the amount of movement of the support column 103 in the vertical direction.
Necessary pins 105 and 106 for holding the column 103 are fixed to the guide 104. The pins 105 are disposed so as to be in contact with the front surface of the support column 103 and the pins 106 are engaged with the grooves 103a.
A fixing screw 107 is screwed on the upper rear surface of the guide 104. The distal end of the fixing screw 107 is in contact with the back surface of the support column 103.

  When adjusting the height of the armrest 102, the fixing screw 107 is loosened, the locked state between the pin 106 and the groove 103a is released, the column 103 is slightly inclined and moved in the longitudinal direction, and the pin 106 and the groove are moved at an appropriate position. 103a is locked. Thereafter, the fixing screw 107 is tightened to hold the locked state.

  By the way, in this armrest device 100, means for preventing loosening of the fixing screw 107 is not provided. For this reason, the fixing screw 107 may be loosened due to insufficient tightening or vibration of the fixing screw 107. When the fixing screw 107 is loosened, the locking state between the pin 106 and the groove 103a is released, and there is a problem that the armrest 102 may fall if the support column 103 is tilted a little.

  The present invention has been made in view of the above-described problems, and can prevent loosening of the fastener related to fixing the height position of the armrest, and inadequate tightening of the fastener. An object of the present invention is to provide an armrest device for a construction machine that can prevent the armrest from falling even if the fastener is loosened due to the cause.

In order to achieve the above object, an armrest device for a construction machine according to a first invention comprises:
An armrest device for a construction machine in which an armrest on which an elbow is placed is configured to be adjustable in height,
A first column supporting the armrest;
A second support column that supports the first support column in a vertically movable manner;
A fastener for fixing the relative position of the first strut to the second strut;
A round bar fixed to one of the first support column and the second support column in the vertical direction; and provided at a position facing the round bar on the other of the first support column and the second support column, A loosening prevention means constituted by a groove portion relatively movable in the vertical direction in contact with the round bar;
A fall prevention means for preventing the armrest from falling by stopping the relative movement in the vertical direction of the first strut with respect to the second strut when the fastener is not fixed;
It is characterized by providing.

In the first invention,
Each of the first support column and the second support column is a square cylindrical column,
The first strut is inserted into the second strut;
The one side plate portion of the second support column is provided with a long hole having a length corresponding to the amount of movement of the first support column in the vertical direction.
A first insertion hole corresponding to the elongated hole is provided in one side plate portion of the first support column,
A nut member having a female screw portion corresponding to the first insertion hole is fixed to one side plate portion of the first support column.
The other side plate portion of the first support column is provided with a second insertion hole corresponding to the female screw portion,
The fastener includes a screw shaft having a male screw portion screwed into the female screw portion through the elongated hole and the first insertion hole.
The fall prevention means is
A plurality of locking holes provided at a predetermined pitch on the other side plate portion of the second column according to the amount of vertical movement of the first column;
A locking shaft portion that is formed on the same axis as the male screw portion, and that can be inserted into one locking hole selected from the plurality of locking holes through the second insertion hole;
It can be said that it is comprised by (2nd invention).

In the first invention,
Each of the first support column and the second support column is a square cylindrical column,
The first strut is inserted into the second strut;
An insertion hole is provided in one side plate portion of the second support column,
One side plate portion of the first support column has a plurality of locking holes provided at a predetermined pitch according to the amount of vertical movement of the first support column, and an inner diameter of the locking hole between the locking holes. A long hole consisting of a straight hole with a width smaller than the dimension is provided,
Inside the first support column, a nut member having a female screw portion corresponding to the insertion hole and a detent plate are incorporated so as to be movable in the vertical direction,
The fastener includes a screw shaft having a male screw portion to be screwed into the female screw portion through the insertion hole and the elongated hole.
The fall prevention means is
The plurality of locking holes provided in one side plate of the first support column;
A locking shaft portion that is formed on the same axis as the male screw portion and is engageable with one locking hole selected from the plurality of locking holes through the insertion hole;
(3rd invention).

In the third invention,
It is preferable that a spring is provided to apply an urging force to the screw shaft to move the locking shaft portion in a direction to push the locking shaft portion into the locking hole (fourth invention).

In the first invention,
Each of the first support column and the second support column is a square cylindrical column,
The first strut is inserted into the second strut;
One side plate portion of the second support column has a plurality of locking holes provided at a predetermined pitch according to the amount of vertical movement of the first support column, and an inner diameter of the locking hole between the locking holes. A long hole consisting of a straight hole with a width smaller than the dimension is provided,
An insertion hole corresponding to the elongated hole is provided in one side plate portion of the first support column,
Inside the first column, a nut member having a female screw portion corresponding to the insertion hole is incorporated movably between one side plate portion and the other side plate portion of the first column,
The fastener includes a screw shaft having a male screw portion screwed into the female screw portion through the elongated hole and the insertion hole,
The fall prevention means is
The plurality of locking holes provided in one side plate of the second column;
A locking shaft portion formed on the same axis as the male screw portion and engageable with one locking hole selected from the plurality of locking holes;
(5th invention).

In the fifth invention,
It is preferable that a spring is provided to apply an urging force to the screw shaft to move the locking shaft portion in a direction in which the locking shaft portion is pushed into the locking hole (sixth invention).

In the first invention,
Each of the first support column and the second support column is a square cylindrical column,
The first strut is inserted into the second strut;
An insertion hole is provided in the side plate portion of the second support column,
The fall prevention means is
A plurality of locking holes provided in the side plate portion of the first support column so as to correspond to the insertion hole at a predetermined pitch according to the amount of movement of the first support column in the vertical direction;
A plunger that can be engaged with one locking hole selected from the plurality of locking holes through the insertion hole;
(7th invention).

In a seventh aspect of the present invention, it is preferable that a spring is provided that applies a biasing force to the plunger to move the plunger in a direction to push the plunger into the locking hole (eighth aspect).

In the armrest device for a construction machine according to the first invention, the first support column supporting the armrest is supported by the second support column so as to be movable in the vertical direction. The relative position of the first strut with respect to the second strut is fixed by a fastener. The fastener is involved in fixing the height position of the armrest.
The round bar fixed to one of the first column and the second column and the groove provided on the other of the first column and the second column are brought into contact with each other. The relative movement of the first support column and the second support column in the direction of loosening is stopped. Thereby, it can prevent reliably that a fastener loosens with a simple structure.
Even when the fastener is loose due to insufficient fastening of the fastener, the vertical movement of the first support with respect to the second support is stopped by the fall prevention means. Thereby, it can prevent that an armrest falls.
According to the armrest device of the construction machine according to the first invention, it is possible to prevent loosening of the fastener related to fixing the height position of the armrest. Moreover, even if the fastener is loosened due to insufficient fastening of the fastener or the like, the armrest can be prevented from falling.

  In the armrest device for a construction machine according to the second invention, a locking shaft portion formed on the same axis as the male screw portion on the screw shaft of the fastener has a second insertion hole provided in the first support column. , And protruding from the selected locking hole through one locking hole selected from the plurality of locking holes provided in the second support column. Thereby, even if the fastener is loosened due to insufficient tightening of the fastener or the like, it is possible to reliably prevent the armrest from falling with a simple configuration.

  In the armrest device for a construction machine according to the third invention, the locking shaft portion formed on the same axis as the male screw portion on the screw shaft of the fastener has a plurality of locking holes provided in the first support column. It is engaged with one locking hole selected from the inside. Thereby, even if the fastener is loosened due to insufficient tightening of the fastener or the like, it is possible to reliably prevent the armrest from falling with a simple configuration.

In the armrest device for a construction machine according to the fourth aspect of the present invention, a spring is provided that applies a biasing force that moves the locking shaft portion in a direction to push the locking shaft portion into the locking hole to the screw shaft of the fastener. In this manner, the locking shaft portion is urged toward the locking hole without any force, so that the insertion operation of the locking shaft portion into the locking hole can be performed more easily.
In addition, unless the fastener is pulled so as to separate the locking shaft portion from the locking hole against the biasing force of the spring, that is, unless the engagement release operation is performed with a clear intention, the locking shaft portion and The engaged state with the locking hole is not released. For this reason, even if some vibration or impact is applied to the fastener or the fastener is unexpectedly contacted, the engagement state between the engagement shaft portion and the engagement hole can be stably maintained. .

  In the armrest device for a construction machine according to the fifth aspect of the present invention, the locking shaft portion formed on the same axis as the male screw portion on the screw shaft of the fastener has a plurality of locking holes provided in the second column. It is engaged with one locking hole selected from the inside. Thereby, even if the fastener is loosened due to insufficient tightening of the fastener or the like, it is possible to reliably prevent the armrest from falling with a simple configuration.

In the armrest device for a construction machine according to the sixth aspect of the present invention, a spring is provided that applies an urging force for moving the locking shaft portion in a direction to push the locking shaft portion into the locking hole to the screw shaft of the fastener. In this manner, the locking shaft portion is urged toward the locking hole without any force, so that the insertion operation of the locking shaft portion into the locking hole can be performed more easily.
In addition, unless the fastener is pulled so as to separate the locking shaft portion from the locking hole against the biasing force of the spring, that is, unless the engagement release operation is performed with a clear intention, the locking shaft portion and The engaged state with the locking hole is not released. For this reason, even if some vibration or impact is applied to the fastener or the fastener is unexpectedly contacted, the engagement state between the engagement shaft portion and the engagement hole can be stably maintained. .

  In the armrest device for a construction machine according to the seventh aspect of the present invention, the plunger is selected from a plurality of locking holes provided in the first support through the insertion hole provided in the second support. Engage with the stop hole. Thereby, even if the fastener is loosened due to insufficient tightening of the fastener or the like, it is possible to reliably prevent the armrest from falling with a simple configuration.

In the armrest device for a construction machine according to the eighth aspect of the present invention, a spring is provided that applies an urging force that moves the plunger in a direction to push the plunger into the locking hole. In this manner, the plunger is urged toward the locking hole without being pushed, so that the insertion operation of the plunger into the locking hole can be performed more easily.
Also, unless the plunger is pulled so that the plunger is pulled away from the locking hole against the biasing force of the spring, that is, unless the engagement is released with a clear intention, the engagement between the plunger and the locking hole The state is not released. For this reason, even if some vibration or impact is applied to the plunger or the plunger is contacted unexpectedly, the engagement state between the engagement shaft portion and the engagement hole can be stably maintained.

1 is an overall perspective view of a hydraulic excavator including an armrest device according to a first embodiment of the present invention. Overall perspective view of the driver's seat unit Overall perspective view of console The principal part longitudinal cross-sectional view (a) of the armrest apparatus which concerns on 1st Embodiment, AA sectional view (b) of (a), BB sectional drawing (c) of (a), and (a) C arrow view (d) Part D enlarged view of FIG. Sectional view taken along line EE in FIG. It is explanatory drawing of the armrest height adjustment operation | movement of the armrest apparatus of 1st Embodiment, and is a principal part longitudinal cross-sectional view (a) showing the latching release state, and the FF sectional view taken on the line (b) of (a). The principal part longitudinal cross-sectional view (a) of the armrest apparatus which concerns on 2nd Embodiment, GG sectional view (b) of (a), HH sectional view (c) and (a) of (a) I arrow view (d) Enlarged view of part J in Fig. 8 (a) It is explanatory drawing of the armrest height adjustment operation | movement of the armrest apparatus of 2nd Embodiment, The principal part longitudinal cross-sectional view (a) showing the locked state, KK sectional view (b) of (a), Unlocking Longitudinal sectional view (c) and LL line sectional view (d) in (c) showing the state The principal part longitudinal cross-sectional view (a) of the armrest apparatus which concerns on 3rd Embodiment, MM sectional view (b) of (a), and NN sectional view (c) of (a) Enlarged view of part O in FIG. It is explanatory drawing of the armrest height adjustment operation | movement of the armrest apparatus of 3rd Embodiment, The principal part longitudinal cross-sectional view (a) showing the latching state, PP line sectional drawing (b) of (a), Unlocking Main part longitudinal cross-sectional views (c) and Q-Q line cross-sectional view (d) showing the state (d) The left view (a) and back view (b) of the principal part of the armrest apparatus concerning the 4th Embodiment of this invention 14B is a cross-sectional view taken along the line RR in FIG. 14A, a cross-sectional view taken along the line S-S in FIG. 14A, and a cross-sectional view taken along the line TT in FIG. It is explanatory drawing of the armrest height adjustment operation | movement of the armrest apparatus of 4th Embodiment, The principal part longitudinal cross-sectional view (a) showing the latching state, UB sectional view (b) of (a), Unlocking Main part longitudinal cross-sectional view (c) which represents a state, and the VV sectional view (d) of (c) Illustration of prior art

Next, a specific embodiment of an armrest device for a construction machine according to the present invention will be described with reference to the drawings.
In addition, embodiment described below is an example by which this invention was applied to the armrest apparatus assembled | attached to the console arrange | positioned at the driver's seat unit of a hydraulic shovel. However, the present invention is not limited to this, and it goes without saying that the present invention is also applied to an armrest device mounted on a construction machine other than a hydraulic excavator, for example, a bulldozer or a wheel loader. In the following description, the front / rear and left / right directions are made to coincide with the front / rear and left / right directions based on the operator seated on the driver's seat (operator seat) unless otherwise specified.

[First Embodiment]
<General description of hydraulic excavator: See FIG. 1>
A hydraulic excavator 1 shown in FIG. 1 includes a lower traveling body 2 including a crawler traveling device 2a.
An upper swing body 3 is installed on the lower traveling body 2 so as to be freely rotatable.
A work machine 7 having a boom 4, an arm 5, and a bucket 6 rotatably connected to each other is attached to the front center portion of the upper swing body 3 so as to be able to bend up and down.
A cab 8 that constitutes a driver's cab is installed on the front left portion of the upper swing body 3.
An engine room 11 that is partitioned by a cover such as an engine hood 10 is provided at the rear part of the upper swing body 3 with a counterweight 9 mounted at the rearmost part.

<Overview of driver's seat unit: see FIG. 2>
As shown in FIG. 2, a driver seat unit 13 is installed on the floor member 12 in the cab 8.
The driver seat unit 13 includes a pedestal 14 fixed on the floor member 12. An operator seat 16 is mounted on the pedestal 14 via a suspension device 15 so as to be movable in the front-rear direction. Consoles 17 and 17 ′ are arranged on the left and right sides of the operator seat 16, respectively.
The left and right consoles 17 and 17 'are configured such that operation levers 19 and 19' of the work machine, armrest devices 20 and 20 ', etc. are collectively arranged on console housings 18 and 18' constituting the main body. Yes.
The armrest devices 20 and 20 'disposed on the left and right consoles 17 and 17' basically have the same structure. As a representative, the armrest device 20 disposed on the left console 17 will be described below.

<Schematic description of armrest device: see FIG. 3>
As shown in FIG. 3, the armrest device 20 is configured such that the armrest 20 a on which the elbow is placed can be adjusted in height.
The armrest device 20 includes a square cylindrical inner column 21 that supports the armrest 20a. The inner column 21 is inserted into a rectangular cylindrical outer column 22 that is erected on the console housing 18. The outer support column 22 supports the inner support column 21 so as to be movable in the vertical direction.

<Explanation of inner struts: see FIGS. 4A and 5>
As shown in FIG. 4A, an armrest support portion 23 that supports the armrest 20 a so as to be rotatable in the vertical direction is formed on the top portion of the inner support column 21.
A leg portion 24 is formed below the inner support column 21 and extends straight downward along the rear plate portion 22a of the outer support column 22.
As shown in FIG. 5, a circular first insertion hole 25 is provided in the rear side plate portion 21 a in the middle portion in the vertical direction of the inner support column 21.
A nut member 26 having a female screw portion 26 a corresponding to the first insertion hole 25 is fixed to the inner surface of the rear plate portion 21 a of the inner support column 21.
A circular second insertion hole 27 corresponding to the female screw portion 26 a of the nut member 26 is provided in the front side plate portion 21 b of the inner column 21.

<Explanation of outer support: see FIGS. 4D, 5 and 7B>
As shown in FIGS. 5 and 7B, a long hole 28 having a length corresponding to the amount of movement of the inner column 21 in the vertical direction is provided in the rear side plate portion 22 a of the outer column 22. The long hole 28 has a rounded rectangular shape, and is disposed so as to correspond to the first insertion hole 25 provided in the rear side plate portion 21 a of the inner column 21.
As shown in FIGS. 4D and 5, the front plate portion 22 b of the outer support column 22 has four locking holes 29 at a predetermined pitch in the vertical direction according to the vertical movement amount of the inner support column 21. .., 29 are provided. These locking holes 29,..., 29 are all round and are arranged so as to correspond to the second insertion holes 27 provided in the front side plate portion 21 b of the inner column 21.

<Description of fastener: see FIG. 5>
As shown in FIG. 5, the inner column 21 and the outer column 22 are fastened by a fastener 30. Thereby, the relative position of the inner column 21 with respect to the outer column 22 is fixed.
The fastener 30 is configured by providing a knob 30b at the proximal end of the screw shaft 30a. The screw shaft 30a includes a first shaft portion 31, a first male screw portion 32, a second shaft portion 33, a second male screw portion 34, and a third shaft that are sequentially formed on the same axis line from the knob 30b side toward the tip end side. Each has a shaft portion 35.
The first shaft portion 31 is set to have a diameter that allows the outer peripheral portion of its end face to contact the periphery of the long hole 28 of the outer support column 22.
The first male screw portion 32 is screwed into the female screw portion 26 a of the nut member 26 fixed to the inner column 21 through the long hole 28 of the outer column 22 and the first insertion hole 25 of the inner column 21.
The second shaft portion 33 has a smaller diameter than the first male screw portion 32 and serves as an intermediate shaft that connects the first male screw portion 32 and the second male screw portion 34.
The second male screw portion 34 has the same diameter and the same pitch as the first male screw portion 32, and the nut member 26 prevents the fastener 30 from being detached when the first male screw portion 32 is detached from the nut member 26. Functions as a stopper to be caught.
The third shaft portion 35 has its selected locking hole through the second insertion hole 27 in the inner column 21 and one locking hole 29 selected from the four locking holes 29 in the outer column 22. The shape dimension is set so that it can protrude from the terminal 29 with a predetermined protrusion amount.

<Schematic description of height adjustment mechanism: see FIG. 6>
As shown in FIG. 6, a height adjustment mechanism 40 is incorporated in the outer support column 22. The height adjustment mechanism 40 is a mechanism that adjusts the height position of the armrest 20a in stages by adjusting the relative position of the inner support 21 with respect to the outer support 22 in stages. The height adjustment mechanism 40 includes a detent spring 41 and a plate member 42.

<Description of detent spring: See FIG. 6>
The detent spring 41 is fixed to the bottom plate portion 21e of the inner column 21. The detent spring 41 is formed by being bent into an inverted U shape having two leg plate portions 41b and 41b extending downward from both side portions of the upper surface plate portion 41a. At the lower end portion of each leg plate portion 41b, an engagement mountain portion 43 is formed that is bent inwardly into a mountain shape. In the detent spring 41, the side surface portion of the plate member 42 can be sandwiched from both sides in a state where the two leg plate portions 41b and 41b are elastically deformed in a direction to spread outward.

<Description of plate member: See FIG. 6>
The plate member 42 is attached to the inner surface of the rear side plate portion 22 a of the outer support column 22 via a block member 44 in a rising shape. The plate member 42 has an insertion plate portion 42 b that extends upward from an attachment plate portion 42 a fixed to the block member 44 by tightening bolts 45 and is inserted between the two leg plate portions 41 b and 41 b of the detent spring 41. It is made. A pair of left and right engagement valley portions 46, 46 into which a pair of left and right engagement mountain portions 43, 43 of the detent spring 41 are fitted on both sides of the insertion plate portion 42b according to the amount of vertical movement of the inner column 21. Four sets are provided at a predetermined pitch in the vertical direction.

<Functional description of height adjustment mechanism: see FIG. 6>
In this height adjustment mechanism 40, the relative position of the inner column 21 with respect to the outer column 22 is changed by changing the engagement position between the engagement peak portions 43, 43 of the detent spring 41 and the engagement valley portions 46, 46 of the plate member 42. The position of the armrest 20a can be adjusted in stages, and the height position of the armrest 20a can be adjusted in four stages. In addition, the engagement peak portions 43 and 43 of the detent spring 41 are engaged with the engagement valley portions 46 and 46 of the plate member 42, so that these function as a height detection portion so that the left and right can be easily adjusted to the same height. be able to. Further, by forming the engaging valley portions 46 and 46 symmetrically, it is possible to uniformly set how to apply the force necessary to move the armrest 20a up and down.

<Description of loosening prevention means: see FIGS. 4A, 4B, and 4C>
Further, as shown in FIG. 4A, a loosening prevention means 50 is incorporated in the outer support column 22. The loosening prevention means 50 prevents the fastener 30 from loosening by stopping the relative movement of the inner strut 21 and the outer strut 22 in the direction of loosening the fastener 30.
As shown in FIG. 4C, the loosening prevention means 50 is configured to include a round bar 51 and a reaction force receiving plate 52.
The round bar 51 is fixed to the inner surface of the rear side plate portion 22a of the outer support 22 along the vertical direction. In addition, in this round bar 51, in order to correspond to the amount of movement of the inner column 21 in the vertical direction, the length dimension thereof is an arrangement region of the four locking holes 29 provided in the outer column 22. It is longer than the vertical distance. Further, regarding the arrangement in the height direction of the round bar 51, the round bar 51 is positioned below the lowermost locking hole 29 of the four locking holes 29,.
The reaction force receiving plate 52 is disposed at a position facing the round bar 51 and is fixed to the lower end portion of the leg portion 24 of the inner column 21. The reaction force receiving plate 52 has a groove 52a. The groove 52a is formed in a V shape having a pair of abutting surfaces that abut the round bar 51 from both sides. When the inner strut 21 moves in the vertical direction, the reaction force receiving plate 52 is relative to the outer strut 22 in a state where the pair of abutting surfaces of the groove 52 a abuts the outer peripheral surface of the round bar 51. Therefore, it can be moved vertically.
By the way, when a left-right load F (see FIG. 4B) is applied to the armrest 20a, the inner strut 21 becomes the outer strut 22 within the range of the left-right clearance between the inner strut 21 and the outer strut 22. On the other hand, the fastener 30 rotates in the left-right direction about the screw shaft 30a. The fastener 30 may be loosened by the rotation of the inner column 21 in the left-right direction.
In the loosening prevention means 50, the groove portion 52a of the reaction force receiving plate 52 is brought into contact with the round bar 51 at an arbitrary position within the vertically movable range of the inner support column 21, thereby rotating the inner support column 21 in the left-right direction. The reaction force to prevent is secured. For this reason, the direction in which the fastener 30 is loosened, in other words, the direction in which the nut member 26 is loosened relative to the male screw portion 32 of the fastener 30, that is, the clockwise direction about the screw shaft 30a of the fastener 30 as viewed from the rear side (right Rotation of the inner strut 21 with respect to the outer strut 22 in the direction of rotation) can be stopped, and the fastener 30 can be reliably prevented from loosening.
In addition to the mode in which the round bar 51 is fixed to the outer column 22, there may be a mode in which a required portion of the outer column 22 is drawn to form a convex portion corresponding to the round bar 51. Further, the mounting positions of the round bar 51 and the reaction force receiving plate can be reversed.

<Description of fall prevention means: see FIG. 5>
In the unlikely event that the fastener 30 is loose due to insufficient tightening of the fastener 30 or the like, the fall prevention means 55 is provided to prevent the armrest 20a from dropping. The fall prevention means 55 includes four locking holes 29,... 29 provided in the outer support column 22 and a third shaft portion 35 provided in the screw shaft 30 a of the fastener 30.
In this fall prevention means 55, the third shaft portion 35 of the fastener 30 is one engagement member selected from the second insertion hole 27 of the inner column 21 and the four locking holes 29,. A predetermined amount of protrusion is projected from the selected locking hole 29 through the stop hole 29. For this reason, even when the fastener 30 is in a somewhat loose state, and even if the fastener 30 is further loosened, as long as the locking hole 29 and the third shaft portion 35 are in the locked state, the The support column 21 and the outer support column 22 are hooked to each other by the third shaft portion 35, and the relative movement in the vertical direction of the inner support column 21 with respect to the outer support column 22 is stopped. Thereby, it can prevent reliably that the armrest 20a falls.

<Explanation of relationship between height adjustment mechanism and fall prevention means: see FIGS. 4D and 6>
The vertical pitch of the four locking holes 29 shown in FIG. 4 (d) and the four sets of engagement valleys 46, 46 shown in FIG. The pitch is matched. For this reason, when adjusting the relative position of the inner strut 21 with respect to the outer strut 22 by the height adjusting mechanism 40 in four stages, the adjustment of the four locking holes 29,. The height positions of one locking hole 29 corresponding to each stage and the second insertion hole 27 of the inner column 21 can be automatically matched. Therefore, after the height adjustment, it is possible to easily perform a locking operation for causing the third shaft portion 35 to enter the selected locking hole 29.

<Description of Armrest Height Adjustment Operation: See FIGS. 5, 6, and 7A>
When adjusting the height of the armrest 20a, as shown in FIG. 7A, the fastener 30 is loosened until the third shaft portion 35 comes out of the locking hole 29. At this time, even if the fastener 30 is loosened until the first male screw portion 32 is detached from the nut member 26, the second male screw portion 34 is caught by the nut member 26, thereby preventing the fastener 30 from falling off. Can do.
Next, holding the armrest 20a or the knob 30b of the fastener 30, the inner strut 21 is moved vertically with respect to the outer strut 22, and the armrest 20a is adjusted to a desired height position. At this time, the armrest 20a can be easily adjusted to a four-stage height position by the height adjustment mechanism 40 (see FIG. 6). Note that the urging force with which the detent spring 41 sandwiches the plate member 42 can prevent the armrest 20a from falling naturally even before the fastener 30 is tightened, and the armrest 20a can be held at a preferred height position. .
When the desired height position of the armrest 20a is determined, the fastener 30 is tightened so that the first male screw portion 32 is screwed into the female screw portion of the nut member 26, and the relative position of the inner column 21 with respect to the outer column 22 To fix. At this time, as shown in FIG. 5, the third shaft portion 35 of the fastener 30 passes through the second insertion hole 27 of the inner support column 21 from among the four locking holes 29,. It rushes into one selected locking hole 29.

<Description of Effects of First Embodiment: See FIG. 4A>
In the armrest device 20 of the first embodiment, the relative movement of the inner strut 21 and the outer strut 22 in the direction of loosening the fastener 30 is stopped by the loosening prevention means 50. Thereby, it can prevent that the fastener 30 loosens. In addition, even when the fastener 30 is loose (when not fastened) due to insufficient tightening of the fastener 30 or the like, the vertical movement of the inner strut 21 with respect to the outer strut 22 prevents the fall. Stopped by means 55. Thereby, it can prevent that the armrest 20a falls.

[Second Embodiment]
FIG. 8 is a longitudinal sectional view of main parts of an armrest device according to the second embodiment of the present invention (a), a sectional view taken along line GG in (a), and a sectional view taken along line HH in (a). FIGS. 1 (c) and 1 (a) are respectively shown in an arrow I view (d). In the present embodiment, the same or similar parts as those in the first embodiment will be denoted by the same reference numerals in the drawings, and detailed description thereof will be omitted. Hereinafter, the first embodiment is different from the first embodiment. The explanation will focus on points.

<Description of inner strut: see FIGS. 8A, 8D, 9 and 10B>
As shown in FIG. 8A, a long hole 56 having a length corresponding to the amount of movement of the inner column 21 in the vertical direction is provided in the rear side plate portion 21a in the middle portion of the inner column 21 in the vertical direction. Yes. Further, as shown in FIG. 10 (b), the rear plate portion 21a of the inner column 21 has four round-shaped engagements at a predetermined pitch in the vertical direction according to the amount of movement of the inner column 21 in the vertical direction. The holes 57,..., 57 are provided integrally with the long hole 56. In the long hole 56, a straight straight hole 58 is formed between the locking holes 57 and 57 adjacent to each other. The width dimension of the straight hole 58 in the left-right direction is smaller than the inner diameter dimension of the locking hole 57.
As shown in FIG. 9, a nut member 59 having a female screw portion 59 a corresponding to the long hole 56 is disposed in the inner column 21 so as to be movable in the vertical direction.
A nut guide plate 60 is fixed to the inner surface of the rear plate portion 21a of the inner support column 21. The nut guide plate 60 has a slit portion 60a extending in the vertical direction.
As shown in FIG. 8D, the nut member 59 is guided in the vertical direction by fitting the nut member 59 into the slit portion 60a.

<Description of detent plate: see FIG. 8 (d), FIG. 9>
As shown in FIG. 9, a detent plate 61 is incorporated between the inner surface of the rear side plate portion 21 a of the inner column 21 and the nut guide plate 60.
As shown in FIG. 8 (d), the detent plate 61 is formed of a square plate-like member that can approach each of the left plate portion 21 c and the right plate portion 21 d of the inner column 21.
As shown in FIG. 9, the non-rotating plate 61 is provided with a round hole 61a having a diameter sufficiently larger than the female screw portion 59a of the nut member 59 so as to be positioned on the same axis as the female screw portion 59a. Yes. The nut member 59 and the rotation prevention plate 61 are fixed, and both are integrally movable in the vertical direction by the guide of the nut guide plate 60.
Then, at any position in the vertical movement range of the inner column 21, when the fastener 30 is tightened and released from the nut member 59, the left side and the right side of the detent plate 61 are respectively connected to the inner column 21. Each of the left side plate portion 21c and the right side plate portion 21d is brought into contact with the right side plate portion 21d so as to ensure a reaction force against the rotational operation force of the fastener 30. Thus, the nut member 59 can be prevented from rotating together with the fastener 30, and the fastening / tightening operation of the fastener 30 with respect to the nut member 59 can be reliably performed.
In addition, in order to smoothly move the rotation prevention plate 61 in the vertical direction, the rotation prevention plate 61 is appropriately chamfered.

<Explanation of outer support: see Fig. 9>
A circular insertion hole 62 is provided in the rear plate portion 22 a of the outer column 22 so as to correspond to the long hole 56 of the inner column 21.

<Description of fasteners: see FIGS. 9 and 10 (a) and 10 (b)>
The inner support column 21 and the outer support column 22 are fastened by a fastener 30. Thereby, the relative position of the inner column 21 with respect to the outer column 22 is fixed.
The fastener 30 is configured by providing a knob 30b at the proximal end of the screw shaft 30a. The screw shaft 30a has a first shaft portion 65, a second shaft portion 66, a male screw portion 67, and a third shaft portion 68 that are sequentially formed on the same axis from the knob 30b side toward the tip end side. .
The first shaft portion 65 is set to have a diameter that allows the outer peripheral portion of its end face to contact the periphery of the insertion hole 62 of the outer support column 22.
The second shaft portion 66 can be engaged with one locking hole 57 selected from the four locking holes 57,... 57 of the inner column 21 through the insertion hole 62 of the outer column 22. It serves as an intermediate shaft that connects the shaft portion 65 and the male screw portion 67. In addition, since the outer diameter dimension of the 2nd axial part 66 is larger than the width dimension of the straight hole 58 in the long hole 56 of the inner support | pillar 21, the 2nd axial part 66 cannot pass the straight hole 58 (FIG. 10). (See (b)).
The male screw portion 67 is screwed into the female screw portion 59a of the nut member 59 through the insertion hole 62 of the outer support post 22 and the elongated hole 56 of the inner support post 21. In addition, since the outer diameter dimension of the male screw part 67 is smaller than the width dimension of the straight hole 58 in the long hole 56 of the inner column 21, the male screw part 67 can pass through the straight hole 58 (FIG. 10 (d). )reference).
The third shaft portion 68 has a smaller diameter than the male screw portion 67 and is disposed in the female screw portion 59a of the nut member 59. The third shaft portion 68 serves as a guide shaft when the male screw portion 67 is screwed into the female screw portion 59a. do.

<Description of fastener biasing means: see FIG. 9>
A compression coil spring 69 is mounted on the outer periphery of the first shaft portion 65 of the screw shaft 30 a in the fastener 30. The front end of the spring 69 is in contact with an outward flange 65 a provided at the front end of the first shaft portion 65. The rear end of the spring 69 is in contact with an inward flange 70 a of a spring cover 70 that covers the spring 69. The spring cover 70 is fixed to the outer surface of the rear side plate portion 22 a of the outer support column 22.
The spring 69 serves to act on the screw shaft 30a with a biasing force that moves the second shaft portion 66 of the fastener 30 in a direction to push the second shaft portion 66 of the fastener 30 into the locking hole 57 of the inner column 21 through the insertion hole 62 of the outer column 22.

<Description of fall prevention means: see FIGS. 9 and 10B>
In the unlikely event that the fastener 30 is loose due to insufficient tightening of the fastener 30 or the like, the fall prevention means 55A is provided to prevent the armrest 20a from falling. The fall prevention means 55A is composed of four locking holes 57,..., 57 provided in the inner column 21 and a second shaft portion 66 provided in the screw shaft 30a of the fastener 30.
In this fall prevention means 55A, the second shaft portion 66 of the fastener 30 has one locking hole 57 selected from the four locking holes 57,... Engaged. Since the outer diameter size of the second shaft portion 66 is larger than the width size of the straight hole 58 in the long hole 56 of the inner column 21, the second shaft portion 66 cannot pass through the straight hole 58 (FIG. 10B). )reference). For this reason, even when the fastener 30 is in a somewhat loose state, and even if the looseness of the fastener 30 further proceeds and the male screw portion 67 is detached from the nut member 59, the inner strut 21 and the outer strut 22 Are engaged with each other by the second shaft portion 66, and the relative movement in the vertical direction of the inner column 21 with respect to the outer column 22 is stopped. Thereby, it can prevent reliably that the armrest 20a falls.

<Explanation of relationship between height adjustment mechanism and fall prevention means: see FIGS. 6 and 10B>
The vertical pitch of the four locking holes 57 shown in FIG. 10B and the four sets of engagement valleys 46, 46 shown in FIG. The pitch is matched. For this reason, when the height adjustment mechanism 40 adjusts the relative position of the inner strut 21 with respect to the outer strut 22 in four stages, adjustment of the four locking holes 57,... The height positions of one locking hole 57 corresponding to each stage and the insertion hole 62 of the outer support 22 can be automatically matched. Therefore, after the height adjustment, it is possible to easily perform a locking operation for causing the second shaft portion 66 to enter the selected locking hole 57.

<Description of Armrest Height Adjustment Operation: See FIGS. 10 (a) to 10 (d)>
When adjusting the height of the armrest 20a, as shown in FIG. 10A, the fastener 30 is loosened until the male screw portion 67 is detached from the nut member 59. At this time, even if the fastener 30 is loosened until the male screw portion 67 is removed from the nut member 59, the second shaft portion 66 of the fastener 30 has four engagements as shown in FIG. Since the state of being engaged with any one of the holes 57,... 57 is maintained, the inner column 21 and the outer column 22 are hooked to each other by the second shaft portion 66. The relative movement in the vertical direction of the inner column 21 with respect to the outer column 22 is stopped, and the armrest 20a does not fall.
Next, with the armrest 20a held so as to hold the current height position, the second shaft portion 66 is engaged with the locking hole 57 against the urging force of the spring 69 as shown in FIG. The fastener 30 is pulled until it comes off, and further, the fastener is pulled until the spring 69 is fully contracted. Then, as shown in FIG. 4D, the male screw portion 67 of the screw shaft 30a is arranged at the position of the long hole 56 of the inner column 21. Since the male screw portion 67 can pass through the straight hole 58 in the long hole 56, the inner strut 21 can be moved in the vertical direction.
Next, while keeping the state of the fastener 30 pulled until the spring 69 is fully contracted, the armrest 20a is held and the inner strut 21 is moved in the vertical direction with respect to the outer strut 22, and the armrest 20a is moved to a desired height. Adjust to the position. At this time, the armrest 20a can be easily adjusted to a four-stage height position by the height adjustment mechanism 40 (see FIG. 6). Note that the urging force with which the detent spring 41 sandwiches the plate member 42 can prevent the armrest 20a from falling naturally even before the fastener 30 is tightened, and the armrest 20a can be held at a preferred height position. .
Next, when the desired height position of the armrest 20a is determined, the fastener 30 that has been continuously pulled is released. Then, due to the biasing force of the spring 69, the second shaft portion 66 of the fastener 30 passes through the insertion hole 62 of the outer column 22 and is selected from the four locking holes 57,. The male screw part 67 is pressed into the female screw part 59 a of the nut member 59 by being inserted into the locking hole 57.
Then, the fastener 30 is tightened so that the male screw portion 59 is screwed into the female screw portion 59 a, and the relative position of the inner strut 21 with respect to the outer strut 22 is fixed.

<Description of Effects of Second Embodiment: See FIG. 9>
The same effects as the armrest device 20 of the first embodiment can be obtained also by the armrest device 20A of the second embodiment.
Furthermore, in the armrest device 20 </ b> A of the second embodiment, a spring 69 is provided that applies a biasing force that moves the second shaft portion 66 in a direction to push the second shaft portion 66 into the locking hole 57 to the screw shaft 30 a of the fastener 30. Thus, the second shaft portion 66 is urged toward the locking hole 57 with ease, so that the insertion operation of the second shaft portion 66 into the locking hole 57 can be performed more easily. Further, unless the fastener 30 is pulled so as to pull the second shaft portion 66 away from the locking hole 57 against the urging force of the spring 69, that is, unless the engagement release operation is performed with a clear intention, The engaged state between the biaxial portion 66 and the locking hole 57 is not released. For this reason, even if some vibration or impact is applied to the fastener 30 or the fastener 30 is abruptly contacted, the engagement state between the second shaft portion 66 and the locking hole 57 can be stabilized. Can keep.

[Third Embodiment]
FIG. 11 is a longitudinal sectional view of main parts of an armrest device according to a third embodiment of the present invention (a), a sectional view taken along line MM in (a), and a sectional view taken along line NN in (a). Each figure (c) is shown. In the present embodiment, the same or similar parts as those in the first embodiment will be denoted by the same reference numerals in the drawings, and detailed description thereof will be omitted. Hereinafter, the first embodiment is different from the first embodiment. The explanation will focus on points.

<Description of inner strut: see FIG. 11 (a)>
A circular insertion hole 71 is provided in the rear side plate portion 21 a in the middle portion of the inner column 21 in the vertical direction.
A nut member 72 is movably disposed in the inner support column 21 in the front-rear direction.
A nut guide cylinder 73 is fixed to the inner surface of the rear plate portion 21a of the inner column 21.

<Description of nut member: See FIG. 12>
As shown in FIG. 12, the nut member 72 is a boundary between the small-diameter cylindrical portion and the large-diameter cylindrical portion that are sequentially formed on the same axis from the rear plate portion 21 a side to the front plate portion 21 b side of the inner column 21. Has a stepped surface 72a.
A female screw portion 72 b corresponding to the insertion hole 71 of the inner column 21 is formed at the center portion of the nut member 72 with a predetermined length dimension from the rear end position toward the front end side. Further, a hollow portion 72c that is coaxial with the female screw portion 72b is formed at the center portion of the nut member 72 from the female screw portion 72b to the front end position with an inner diameter dimension larger than the inner diameter dimension of the female screw portion 72b. Yes.
An anti-rotation plate portion 72d is integrally provided on the outer peripheral surface of the large-diameter cylindrical portion of the nut member 72.

<Description of non-rotating plate: see FIG. 11B>
As shown in FIG. 11 (b), the rotation prevention plate portion 72 d is formed of a square plate-like member that can approach each of the left side plate portion 21 c and the right side plate portion 21 d of the inner column 21. When the fastener 30 is tightened / unfastened with respect to the nut member 72, the left side portion and the right side portion of the anti-rotation plate portion 72d are in contact with the left side plate portion 21c and the right side plate portion 21d of the inner column 21, respectively. The reaction force that resists the turning operation force of the fastener 30 is ensured. Thus, the nut member 72 can be prevented from rotating together with the fastener 30, and the fastening / tightening operation of the fastener 30 with respect to the nut member 72 can be reliably performed.

<Description of nut guide cylinder: See FIG. 12>
The nut guide cylinder 73 has a hollow portion 73 a into which the small diameter cylindrical portion of the nut member 72 is fitted. The nut member 72 is guided in the front-rear direction by fitting the small-diameter cylindrical portion of the nut member 72 into the hollow portion 73a.
The front end surface of the nut guide cylinder 73 and the stepped surface 72a of the nut member 72 can be brought into contact with each other. Thereby, the nut guide cylinder 73 also serves as a stopper that stops the movement of the nut member 72 toward the rear side at a predetermined position.
The upper half of the front portion of the nut guide cylinder 73 is greatly cut away when the nut member 72 is assembled into the nut guide cylinder 73 through the opening 21f formed at a predetermined position on the front side of the inner column 21. This is to facilitate the assembly work.

<Description of outer support: see FIG. 13B>
A long hole 74 having a length corresponding to the amount of movement of the inner column 21 in the vertical direction is provided in the rear side plate portion 22a of the outer column 22. Further, the rear plate portion 22a of the outer support column 22 has four round locking holes 75,..., 75 at a predetermined pitch in the vertical direction according to the amount of movement of the inner support column 21 in the vertical direction. It is provided integrally. In the long hole 74, a straight straight hole 76 is formed between the adjacent locking holes 75, 75. The width dimension of the straight hole 76 in the left-right direction is smaller than the inner diameter dimension of the locking hole 75.

<Explanation of fasteners: see FIGS. 12, 13 (b) and 13 (d)>
As shown in FIG. 12, the inner column 21 and the outer column 22 are fastened by a fastener 30. Thereby, the relative position of the inner column 21 with respect to the outer column 22 is fixed.
The fastener 30 is configured by providing a knob 30b at the proximal end of the screw shaft 30a. The screw shaft 30a includes a first shaft portion 77, a second shaft portion 78, a first male screw portion 79, a third shaft portion 80, and a second male shaft that are sequentially formed on the same axis line from the knob 30b side toward the tip end side. Each has a screw portion 81.
The first shaft portion 77 is set to have a diameter that allows the outer peripheral portion of its end face to contact the periphery of the long hole 74 of the outer support column 22.
The second shaft portion 78 can be engaged with one locking hole 75 selected from the four locking holes 75 of the outer support column 22, and the first shaft portion 77 and the first male screw. It serves as an intermediate shaft that connects the portion 79. In addition, since the outer diameter dimension of the 2nd axial part 78 is larger than the width dimension of the straight hole 76 in the long hole 74 of the outer support | pillar 22, the 2nd axial part 78 cannot pass the straight hole 76 (FIG. 13). (See (b)).
The first male screw portion 79 is screwed into the female screw portion 72 b of the nut member 72 through the long hole 74 of the outer support post 22 and the insertion hole 71 of the inner support post 21. In addition, since the outer diameter dimension of the 1st male screw part 79 is smaller than the width dimension of the straight hole 76 in the long hole 74 of the outer support | pillar 22, the 1st male screw part 79 can pass the straight hole 76 ( (Refer FIG.13 (d)).
The third shaft portion 80 has a smaller diameter than the first male screw portion 79 and serves as an intermediate shaft that connects the first male screw portion 79 and the second male screw portion 81.
The second male screw portion 81 has the same diameter and the same pitch as the first male screw portion 79, and the nut member 72 prevents the fastener 30 from being detached when the first male screw portion 79 is detached from the nut member 72. Functions as a stopper to be caught.

<Description of fastener biasing means: see FIG. 12>
A compression coil spring 82 is mounted on the outer periphery of the nut member 72 via a nut guide cylinder 73. The front end of the spring 82 is in contact with the detent plate portion 72d. The rear end of the spring 82 is in contact with the inner surface of the rear plate portion 21 a of the inner column 21.
The spring 82 serves to apply an urging force that moves the second shaft portion 78 of the fastener 30 in a direction to push the second shaft portion 78 into the locking hole 75 of the outer support 22 via the nut member 72.

<Description of fall prevention means: see FIGS. 12 and 13B>
In the unlikely event that the fastener 30 is loose due to insufficient tightening of the fastener 30 or the like (when not fastened), a fall prevention means 55B for preventing the armrest 20a from falling is provided. The fall prevention means 55B includes four locking holes 75,..., 75 provided in the outer support column 22, and a second shaft portion 78 provided in the screw shaft 30a of the fastener 30.
In this fall prevention means 55B, the second shaft portion 78 of the fastener 30 is engaged with one locking hole 75 selected from the four locking holes 75,... Combined. Since the outer diameter of the second shaft portion 78 is larger than the width of the straight hole 76 in the long hole 74 of the outer support column 22, the second shaft portion 78 cannot pass through the straight hole 76 (FIG. 13B). )reference). For this reason, even when the fastener 30 is in a somewhat loose state, the inner strut 21 and the outer strut 22 are hooked together by the second shaft portion 78, and the inner strut 21 in the vertical direction with respect to the outer strut 22 is Relative movement is stopped. Thereby, it can prevent reliably that the armrest 20a falls.

<Explanation of relationship between height adjustment mechanism and fall prevention means: see FIGS. 6 and 13B>
The vertical pitches of the four locking holes 75 shown in FIG. 13 (b) and the four sets of engagement valleys 46, 46 shown in FIG. The pitch is matched. For this reason, when the height adjustment mechanism 40 adjusts the relative position of the inner strut 21 with respect to the outer strut 22 in four stages, the adjustment of the four locking holes 75,... The height positions of one locking hole 75 corresponding to each stage and the insertion hole 71 of the inner column 21 can be automatically matched. Therefore, after the height adjustment, it is possible to easily perform a locking operation for inserting the second shaft portion 78 of the screw shaft into the selected locking hole 75.

<Description of Armrest Height Adjustment Operation: See FIGS. 13A to 13D>
When adjusting the height of the armrest 20a, the fastener 30 is sufficiently loosened. At this time, the second shaft portion 78 of the fastener 30 is biased so as to be pushed into the locking hole 75 of the outer support post 22 via the nut member 72 by the spring 82, so that even in FIG. As shown, even if the fastener 30 is loosened until the first male screw portion 79 is disengaged from the nut member 72, the second shaft portion 78 of the fastener 30 has four locking holes 75,. The state of being engaged with any one of the locking holes 75 is maintained. For this reason, the inner strut 21 and the outer strut 22 are hooked to each other by the second shaft portion 78, the vertical movement of the inner strut 21 with respect to the outer strut 22 is stopped, and the armrest 20a falls. There is no.
Next, with the armrest 20a held so as to hold the current height position, the stepped surface 72a of the nut member 72 resists the urging force of the spring 82 as shown in FIG. 13C. The fastener 30 is pulled until it contacts the front end surface of the guide cylinder 73. Then, the second shaft portion 78 is removed from the locking hole 75, and the first male screw portion 79 is further disposed at the position of the long hole 74 of the outer support column 22. As shown in FIG. 13D, the first male screw portion 79 can pass through the straight hole 76 in the long hole 74, so that the inner strut 21 can be moved in the vertical direction.
Next, the inner strut 21 is held with the armrest 20a or the knob 30b of the fastener 30 while keeping the state of the fastener 30 pulled until the stepped surface 72a of the nut member 72 contacts the front end surface of the nut guide cylinder 73. Is moved in the vertical direction with respect to the outer support column 22, and the armrest 20a is adjusted to a desired height position. At this time, the armrest 20a can be easily adjusted to a four-stage height position by the height adjustment mechanism 40 (see FIG. 6). Note that the urging force with which the detent spring 41 sandwiches the plate member 42 can prevent the armrest 20a from falling naturally even before the fastener 30 is tightened, and the armrest 20a can be held at a preferred height position. .
Next, when the desired height position of the armrest 20a is determined, the fastener 30 that has been continuously pulled is released. Then, the second shaft portion 78 of the fastener 30 is plunged into one locking hole 75 selected from the four locking holes 75,... .
Then, the fastener 30 is tightened so that the first male screw portion 79 is screwed into the female screw portion 72 b of the nut member 72, and the relative position of the inner column 21 with respect to the outer column 22 is fixed.

<Description of Effects of Third Embodiment: See FIG. 12>
Also with the armrest device 20B of the third embodiment, the same effects as those of the armrest device 20 of the first embodiment can be obtained.
Further, in the armrest device 20B of the third embodiment, a spring that applies a biasing force that moves the second shaft portion 78 in a direction of pushing into the locking hole 75 to the screw shaft 30a of the fastener 30 via the nut member 72. 82 is provided. In this way, the second shaft portion 78 is pushed toward the locking hole 75 without any force, so that the insertion operation of the second shaft portion 78 into the locking hole 75 can be performed more easily. Further, unless the fastener 30 is pulled so as to separate the second shaft portion 78 from the locking hole 75 against the urging force of the spring 82, that is, unless the engagement releasing operation is performed with a clear intention, The engaged state between the biaxial portion 78 and the locking hole 75 is not released. For this reason, even if some vibration or impact is applied to the fastener 30 or the fastener 30 is abruptly contacted, the engagement state between the second shaft portion 78 and the locking hole 75 is stably maintained. Can keep.

[Fourth Embodiment]
FIG. 14 shows a left side view (a) and a rear view (b) of the main part of the armrest device according to the fourth embodiment of the present invention. FIG. 15 is a cross-sectional view taken along line RR in FIG. 14B, a cross-sectional view taken along line SS in FIG. 14A, and a cross-sectional view taken along line TT in FIG. Are shown respectively. In the present embodiment, the same or similar parts as those in the first embodiment will be denoted by the same reference numerals in the drawings, and detailed description thereof will be omitted. Hereinafter, the first embodiment is different from the first embodiment. The explanation will focus on points.

<Description of inner strut: see FIG. 15 (a)>
As shown in FIG. 15A, a circular insertion hole 83 is provided in the rear side plate portion 21 a in the middle portion in the vertical direction of the inner column 21.
A nut member 84 having a female screw portion 84 a corresponding to the insertion hole 83 is fixed to the inner surface of the rear side plate portion 21 a of the inner column 21.
On the left side plate portion 21c in the middle portion of the inner column 21 in the vertical direction, four locking holes 85,. Is provided.

<Description of outer support: see FIG. 14 (b), FIG. 15 (a), FIG. 16 (a)>
As shown in FIGS. 14B and 15A, the rear plate 22a of the outer support column 22 is provided with a long hole 86 having a length corresponding to the amount of movement of the inner support column 21 in the vertical direction. Yes. The elongated hole 86 has a rounded rectangular shape and is disposed so as to correspond to the insertion hole 83 provided in the rear side plate portion 21a of the inner column 21.
As shown in FIG. 16A, the left side plate portion 22c of the outer column 22 has one locking hole 85 selected from the four locking holes 85 of the inner column 21. A circular insertion hole 87 is provided so as to correspond.

<Description of fastener: see FIG. 15 (a)>
The inner support column 21 and the outer support column 22 are fastened by a fastener 30. Thereby, the relative position of the inner column 21 with respect to the outer column 22 is fixed.
The fastener 30 is configured by providing a knob 30b at the proximal end of the screw shaft 30a. The screw shaft 30a has a shaft portion 88 and a male screw portion 89 that are sequentially formed on the same axis line from the knob 30b side toward the tip end side.
The shaft portion 88 is set to have a diameter that allows the outer peripheral portion of its end face to contact the periphery of the long hole 86 of the outer support column 22.
The male screw portion 89 is screwed into the female screw portion 84 a of the nut member 84 fixed to the inner column 21 through the elongated hole 86 of the outer column 22 and the insertion hole 83 of the inner column 21.

<Description of Plunger Device: See FIGS. 14A, 14B, 16A>
As shown in FIGS. 14A and 14B, a plunger device 90 is attached to the outer support column 22.
As shown in FIG. 16 (a), the plunger device 90 includes a casing portion 92 that is screwed into a nut member 91 that is concentrically fixed to the outer surface of the left side plate portion 22 c of the outer support column 22. ing.
A plunger 93 is incorporated in the casing portion 92.
The plunger 93 can be engaged with one locking hole 85 selected from the four locking holes 85,... 85 through the insertion hole 87 of the outer support column 22.
A flange portion 93 a is formed at the proximal end portion of the plunger 93 so as to project outward.
A connecting shaft 94 is integrally provided on the base end surface of the plunger 93. A knob 95 is attached to the base end portion of the connecting shaft 94 so as to be positioned on the rear side of the casing portion 92. Holding this knob 95, the plunger 93 is inserted into and removed from the locking hole 85.

<Description of plunger biasing means: see FIGS. 16 (a) and 16 (b)>
A compression coil spring 96 that is attached to the outer periphery of the connecting shaft 94 is incorporated in the casing portion 92.
The front end of the spring 96 is in contact with the flange portion 93 a of the plunger 93. The rear end of the spring 96 is in contact with the rear end surface portion of the casing portion 92.
The spring 96 serves to act on the plunger 93 with an urging force that moves the plunger 93 in a direction of pushing the plunger 93 into the locking hole 85 of the inner column 21.

<Description of fall prevention means: see FIGS. 16 (a) and 16 (b)>
In the unlikely event that the fastener 30 is loose due to insufficient fastening or the like, the fall prevention means 55C is provided to prevent the armrest 20a from dropping even when the fastener 30 is loose (when not fastened). The fall prevention means 55 </ b> C includes four locking holes 85,..., 85 provided in the inner support column 21 and a plunger 93.
In the fall prevention means 55C, the plunger 93 is connected through the insertion hole 87 of the outer support 22 and the one locking hole 85 selected from the four locking holes 85,. It protrudes from the stop hole 85. For this reason, even when the fastener 30 is in a loose state, the inner strut 21 and the outer strut 22 are hooked by the plunger 93, and the relative movement in the vertical direction of the inner strut 21 with respect to the outer strut 22 is stopped. It is done. Thereby, it can prevent reliably that the armrest 20a falls.

<Explanation of relationship between height adjustment mechanism and fall prevention means: see FIGS. 6, 16 (a) and 16 (b)>
16 (a) (b), the vertical pitch of the four locking holes 85,..., And the four sets of engagement valleys 46, 46 shown in FIG. The pitch in the vertical direction is matched. For this reason, when adjusting the relative position of the inner strut 21 with respect to the outer strut 22 by the height adjusting mechanism 40 in four stages, the adjustment of the four locking holes 85,. The height positions of one locking hole 85 corresponding to each stage and the insertion hole 87 of the inner column 21 can be automatically matched. Therefore, after the height adjustment, it is possible to easily perform a locking operation for inserting the plunger 93 into the selected locking hole 85.

<Description of Armrest Height Adjustment Operation: See FIGS. 4A and 16A to 16D>
When adjusting the height of the armrest 20a, the fastener 30 is sufficiently loosened. At this time, since the plunger 93 is urged so as to be pushed into the locking hole 85 of the inner column 21 by the spring 96, the plunger 93 has four locking holes 85 as shown in FIG. The state of being engaged with any one of the locking holes 85 is maintained.
Next, with the armrest 20a or the knob 30b of the fastener 30 held so as to maintain the current height position of the armrest 20a, as shown in FIG. The plunger 93 is pulled with the knob 95 until the plunger 93 comes out of the locking hole 85, and further, the plunger 93 is pulled until the spring 96 is fully contracted. Then, the engaged state between the plunger 93 and the locking hole 85 is released, and the inner strut 21 can be moved in the vertical direction.
Next, while maintaining the state of the plunger 93 pulled until the spring 96 is fully contracted, holding the arm rest 20a or the knob 30b of the fastener 30, the inner column 21 is moved vertically with respect to the outer column 22, The armrest 20a is adjusted to a desired height position. At this time, the armrest 20a can be easily adjusted to a four-stage height position by the height adjustment mechanism 40 (see FIG. 6). Note that the urging force with which the detent spring 41 sandwiches the plate member 42 can prevent the armrest 20a from falling naturally even before the fastener 30 is tightened, and the armrest 20a can be held at a preferred height position. .
Next, when the desired height position of the armrest 20a is determined, the knob 95 that has been continuously pulled is released. Then, due to the urging force of the spring 96, the plunger 93 is inserted into one locking hole 85 selected from the four locking holes 85,... 85 of the inner column 21 through the insertion hole 87 of the outer column 22. The
Then, the fastener 30 is tightened so that the male screw portion 89 of the fastener 30 is screwed into the female screw portion 84 a of the nut member 84, and the relative position of the inner strut 21 with respect to the outer strut 22 is fixed.

<Description of Effects of Fourth Embodiment: See FIG. 16>
The effect similar to the armrest apparatus 20 of 1st Embodiment can be acquired also by the armrest apparatus 20C of 4th Embodiment.
Further, in the armrest device 20C of the fourth embodiment, the fall prevention means 55C of the armrest 20a is configured by the plunger device 90 externally attached to the outer support column 22. For this reason, there exists an advantage that it is applicable also to the existing armrest apparatus.

  As mentioned above, although the armrest apparatus of the construction machine of this invention was demonstrated based on several embodiment, this invention is not limited to the structure described in the said embodiment, The structure described in each embodiment is suitably used. The configuration can be changed as appropriate within a range not departing from the gist, such as a combination.

  The armrest device of the construction machine according to the present invention can prevent loosening of the fastener related to fixing the height position of the armrest, and the fastener is loosened due to insufficient fastening of the fastener. However, since it has the characteristic that the armrest can be prevented from falling, it can be suitably used for the application of an armrest device for construction machinery such as a hydraulic excavator, a bulldozer, or a wheel loader.

1 Excavator (construction machine)
20 Armrest device (first embodiment)
20A armrest device (second embodiment)
20B armrest device (third embodiment)
20C armrest device (fourth embodiment)
20a Armrest 21 Inner support (first support)
22 Outer strut (second strut)
25 first insertion hole 26 nut member 27 second insertion hole 28 long hole 29 locking hole 30 fastener 35 third shaft portion (locking shaft portion)
50 Loosening prevention means 51 Round bar 52 Reaction force receiving plate 52a Groove 55 Fall prevention means (first embodiment)
55A fall prevention means (second embodiment)
55B Fall prevention means (third embodiment)
55C fall prevention means (fourth embodiment)
56 long hole 57 locking hole 59 nut member 62 insertion hole 66 second shaft portion (locking shaft portion)
69 Spring 71 Insertion hole 72 Nut member 74 Long hole 75 Locking hole 78 Second shaft part (Locking shaft part)
82 Spring 83 Insertion hole 84 Nut member 85 Locking hole 86 Long hole 93 Plunger 96 Spring

Claims (8)

An armrest device for a construction machine in which an armrest on which an elbow is placed is configured to be adjustable in height,
A first column supporting the armrest;
A second support column that supports the first support column in a vertically movable manner;
A fastener for fixing the relative position of the first strut to the second strut;
A round bar fixed to one of the first support column and the second support column in the vertical direction; and provided at a position facing the round bar on the other of the first support column and the second support column, A loosening prevention means constituted by a groove portion relatively movable in the vertical direction in contact with the round bar;
A fall prevention means for preventing the armrest from falling by stopping the relative movement in the vertical direction of the first strut with respect to the second strut when the fastener is not fixed;
An armrest device for a construction machine, comprising: Each of the first support column and the second support column is a square cylindrical column,
The first strut is inserted into the second strut;
The one side plate portion of the second support column is provided with a long hole having a length corresponding to the amount of movement of the first support column in the vertical direction.
A first insertion hole corresponding to the elongated hole is provided in one side plate portion of the first support column,
A nut member having a female screw portion corresponding to the first insertion hole is fixed to one side plate portion of the first support column.
The other side plate portion of the first support column is provided with a second insertion hole corresponding to the female screw portion,
The fastener includes a screw shaft having a male screw portion screwed into the female screw portion through the elongated hole and the first insertion hole.
The fall prevention means is
A plurality of locking holes provided at a predetermined pitch on the other side plate portion of the second column according to the amount of vertical movement of the first column;
A locking shaft portion that is formed on the same axis as the male screw portion, and that can be inserted into one locking hole selected from the plurality of locking holes through the second insertion hole;
The armrest device for a construction machine according to claim 1, comprising: Each of the first support column and the second support column is a square cylindrical column,
The first strut is inserted into the second strut;
An insertion hole is provided in one side plate portion of the second support column,
One side plate portion of the first support column has a plurality of locking holes provided at a predetermined pitch according to the amount of vertical movement of the first support column, and an inner diameter of the locking hole between the locking holes. A long hole consisting of a straight hole with a width smaller than the dimension is provided,
Inside the first support column, a nut member having a female screw portion corresponding to the insertion hole and a detent plate are incorporated so as to be movable in the vertical direction,
The fastener includes a screw shaft having a male screw portion to be screwed into the female screw portion through the insertion hole and the elongated hole.
The fall prevention means is
The plurality of locking holes provided in one side plate of the first support column;
A locking shaft portion that is formed on the same axis as the male screw portion and is engageable with one locking hole selected from the plurality of locking holes through the insertion hole;
The armrest device for a construction machine according to claim 1, comprising:   The armrest device for a construction machine according to claim 3, wherein a spring is provided that applies an urging force to the screw shaft to move the locking shaft portion in a direction in which the locking shaft portion is pushed into the locking hole. Each of the first support column and the second support column is a square cylindrical column,
The first strut is inserted into the second strut;
One side plate portion of the second support column has a plurality of locking holes provided at a predetermined pitch according to the amount of vertical movement of the first support column, and an inner diameter of the locking hole between the locking holes. A long hole consisting of a straight hole with a width smaller than the dimension is provided,
An insertion hole corresponding to the elongated hole is provided in one side plate portion of the first support column,
Inside the first column, a nut member having a female screw portion corresponding to the insertion hole is incorporated movably between one side plate portion and the other side plate portion of the first column,
The fastener includes a screw shaft having a male screw portion screwed into the female screw portion through the elongated hole and the insertion hole,
The fall prevention means is
The plurality of locking holes provided in one side plate of the second column;
A locking shaft portion formed on the same axis as the male screw portion and engageable with one locking hole selected from the plurality of locking holes;
The armrest device for a construction machine according to claim 1, comprising:   The armrest device for a construction machine according to claim 5, wherein a spring is provided that applies an urging force to the screw shaft to move the locking shaft portion in a direction in which the locking shaft portion is pushed into the locking hole. Each of the first support column and the second support column is a square cylindrical column,
The first strut is inserted into the second strut;
An insertion hole is provided in the side plate portion of the second support column,
The fall prevention means is
A plurality of locking holes provided in the side plate portion of the first support column so as to correspond to the insertion hole at a predetermined pitch according to the amount of movement of the first support column in the vertical direction;
A plunger that can be engaged with one locking hole selected from the plurality of locking holes through the insertion hole;
The armrest device for a construction machine according to claim 1, comprising:   The armrest device for a construction machine according to claim 7, wherein a spring is provided to apply a biasing force to the plunger to move the plunger in a direction to push the plunger into the locking hole.

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