JP3662517B2

JP3662517B2 - Cab mount structure

Info

Publication number: JP3662517B2
Application number: JP2001150832A
Authority: JP
Inventors: 真路吉田
Original assignee: Hino Motors Ltd
Current assignee: Hino Motors Ltd
Priority date: 2001-05-21
Filing date: 2001-05-21
Publication date: 2005-06-22
Anticipated expiration: 2021-05-21
Also published as: JP2002337731A

Description

【０００１】
【発明の属する技術分野】
本発明は、トラックのキャブをシャシフレームにマウントによって支持した固定式のキャブマウント構造に関するものである。
【０００２】
【従来の技術】
キャブオーバトラックには図１で示すように、シャシフレーム１の前方の複数個所におけるキャブマウント部３でキャブ２をマウント部材によって結合した固定式キャブとがある。従来の固定式キャブのマウント構造は図４で示すように、シャシフレーム１側に側壁６によって凸形状をなす支持面５を備えた支持部４を備え、キャブ２側に側壁２１によって凹形状をなし前記支持面５に支持される被支持面９を備えた被支持部８を形成し、前記支持面５と被支持面９にはマウント部材１３のロックボルトを貫通する第２、第１ロックボルト穴７、１０が開設されており、被支持面９を支持面５にマウント部材１３を介して支持させて結合固定している構造である。
【０００３】
【発明が解決しようとする課題】
キャブ２をシャシフレーム１に組み付けるときにはホイスト等によってシャシフレーム１上にキャブ２を下降している。このとき上記従来の構造では支持部４に対し被支持部８が正規の位置に必ず下降するとは限らず、車両の前後あるいは左右にズレて支持すると図５で示すように、支持面５の第２ロックボルト穴７に対し被支持面９の第１ロックボルト穴１０がズレる。従って、第１ロックボルト穴１０がズレて支持された場合はキャブ２を少し上昇して作業者が第１ロックボルト穴１０を支持部５の第２ロックボルト穴７と対応するようキャブ２を誘導しながら再下降したり、下降の当初から作業者がキャブ２を注意深く誘導する等を行う面倒な組み付け作業を必要としていた。
【０００４】
本発明の目的は、簡単な構造によりキャブの被支持部をシャシフレームの支持部の正規位置に位置決めして支持されるようにしたキャブマウント構造を提供することである。
【０００５】
【課題を解決するための手段】
上記の目的を達成するための本発明は、請求項１に記載の通り、トラックのキャブをシャシフレーム１にマウント部材１３によって支持した固定式のキャブマウント構造であって、キャブ側に車両の前後左右方向の軸線と平行な４辺の側壁２１によって凹形状をなし前記マウント部材１３の第１ロックボルト穴１０が開設されている被支持面９を有する角形で隅にアール部Ｒを形成した被支持部８を備え、シャシフレーム１側に前記マウント部材１３の第２ロックボルト穴７が開設されている支持面５と、前記第２ロックボルト穴７を中心にして車両の前後左右方向の軸線と平行で、かつ前記被支持部８の各側壁２１の辺長Ｂ２と略同一辺長Ｂ１の４辺の側壁６によって凸形状をなす支持部４を備え、前記支持部４の各側壁６の外面に前記被支持部８の側壁２１を案内するガイドプレート１１を固設し、前記ガイドプレート１１は上部に外側方向にアール部ｒをもって傾斜した傾斜面１２が形成されこの傾斜面１２より下方に前記支持面５に対し直角な面で前記被支持部８の側壁２１を案内する位置決め面Ｈ２を備えており、前記ガイドプレート１１により被支持面９の第１ロックボルト穴１０を支持面５の第２ロックボルト穴７に対し一致するようにしたことを特徴とするものである。
【０００６】
また、上記の目的を達成するための本発明は、請求項２に記載の通り、トララックのキャブをシャシフレーム１にマウント部材１３によって支持した固定式のキャブマウント構造であって、キャブ側に車両の前後左右方向の軸線と平行な４辺の側壁２１によって凹形状をなし前記マウント部材１３の第１ロックボルト穴１０が開設されている被支持面９を有する角形で隅にアール部Ｒを形成した被支持部８を備え、シャシフレーム１側に前記マウント部材１３の第２ロックボルト穴７が開設されている支持面５０と、前記支持面５０に前記第２ロックボルト穴７を中心にして車両の前後左右方向の軸線と平行で、かつ前記被支持部８の各側壁２１の辺長Ｂ２より僅かに大きな辺長Ｂ３の４辺の側壁１１０を形成した凹形状で角型の支持部４０を備え、前記支持部４０の側壁１１０は上部に外側方向にアール部ｒをもって傾斜した傾斜面１２が形成されこの傾斜面１２より下方の前記支持面５０に対し直角な面で前記被支持部８の側壁２１を案内する位置決め面Ｈ２を備えており、前記支持部４０の側壁１１０により被支持面９の第１ロックボルト穴１０を支持面５０の第２ロックボルト穴７に対し一致するようにしたことを特徴とするものである。
【０００７】
【発明の実施の形態】
以下本発明の実施の形態を図面に基づいて説明する。図１において、１はシャシフレーム、２は前記シャシフレーム１上に固定されたキャブ、３はシャシフレーム１の前方の複数個所におけるキャブマウント部３である。
【０００８】
【実施例１】
図２は本発明の実施例１を示す。図２において、２はキャブである。このキャブ２側に車両の前後左右方向の軸線と平行な各辺長Ｂ２とする４辺の側壁２１によって凹形状をなし被支持面９を備えた角形で隅にアール部Ｒを形成した被支持部８が設けられている。１はシャシフレームである。このシャシフレーム１側に前記被支持部８の各側壁２１の辺長Ｂ２と略同一辺長Ｂ１の４辺の側壁６によって凸形状をなし支持持面５を備えた角形の支持部４が設けられており、前記被支持面９にはマウント部材１３のロックボルト１４を貫通する第１ロックボルト穴１０が、また支持面５にはマウント部材１３のロックボルト１４を貫通する第２ロックボルト穴７が開設されている。
【０００９】
前記支持部４の各側壁６の外面には前記被支持部８を案内するガイドプレート１１が前記第２ロックボルト穴７を中心にして固設されている。このガイドプレート１１は上部に外側方向にアール部ｒをもって傾斜した傾斜面１２が形成されこの傾斜面１２より下方に支持面９に対し直角な面で前記被支持部８各側壁面２１が当接する位置決め面Ｈ２を備えている。
【００１０】
前記ガイドプレート１１の１実施例として、前記被支持部８が支持部４にマウント部材１３を介して支持された状態において傾斜面１２の傾斜角度θは２０°〜５０°、支持面９から傾斜面１２の頂点までの高さＨ１は５０ｍｍ、位置決め面Ｈ２は被支持部８の隅のアール部Ｒとガイドプレート１１の傾斜面１２の基部のアール部ｒとの間の直線部を１０ｍｍを標準とするが、これは車種によって適当な数値に適宜設定される。また、被支持面９の側壁２１辺長Ｂ２は支持部４の各側壁６の辺長Ｂ１より小さくし隙間ｔを設けることが望ましい。
【００１１】
前記マウント部材１３は従来より周知の構造である。すなわち、前記ロックボルト１４、カラー１５、ナット１６、アッパマウントゴム１７、アッパワッシャ１８、ロアマウントゴム１９、ロアワッシャ２０とによって構成されている。
【００１２】
【実施例２】
図３は本発明の実施例２を示す。図３において、２はキャブである。このキャブ２側に車両の前後左右方向の軸線と平行な各辺長Ｂ２とする４辺の側壁２１によって凹形状をなし被支持面９を備えた角形で隅にアール部Ｒを形成した被支持部８が設けられており前記被支持面９にはマウント部材１３のロックボルト１４を貫通する第１ロックボルト穴１０が開設されている点は実施例１と同じ構造である。
【００１３】
この実施例２ではシャシフレーム１側にマウント部材１３の第２ロックボルト穴７が開設されている支持面５０と、前記支持面５０に前記第２ロックボルト穴７を中心にして車両の前後左右方向の軸線と平行で、かつ被支持部８の各側壁２１の辺長Ｂ２より僅かに大きな辺長Ｂ３の４辺の側壁１１０を形成した凹形状の支持部４０を備えた構造であり、前記側壁１１０は上部に外側方向にアール部ｒをもって傾斜した傾斜面１２が形成されこの傾斜面１２より下方に前記支持面５０に対し直角な面で前記被支持部８を案内する位置決め面Ｈ２を備えている。
【００１４】
前記側壁１１０の１実施例として、実施例１と同様に被支持部８が支持部４０にマウント部材１３を介して支持された状態において傾斜面１２の傾斜角度θは２０°〜５０°、支持面９から傾斜面１２の頂点までの高さＨ１は５０ｍｍ、位置決め面Ｈ２は被支持部８の隅のアール部Ｒと側壁１１０の傾斜面１２の基部のアール部ｒとの間の直線部を１０ｍｍを標準とするが、これは車種によって適当な数値に適宜設定される。また、被支持面９の側壁２１辺長Ｂ２は側壁１１０の内側辺長Ｂ３より小さくし隙間ｔを設けることが望ましい。
【００１５】
本発明は上記の通りの構造であるから、実施例１及び実施例２の何れにおいても、支持面５、５０上にアッパマウントゴム１７をアッパワッシャ１８と共に第２ロックボルト穴７の位置にセットした状態でキャブ２をホイスト等によってシャシフレーム１上に下降することにより、被支持部８が実施例１では支持部４に、実施例２では支持部４０対し多少のズレがあっても被支持部８の側壁２１が実施例１ではガイドプレート１１の、実施例２では側壁１１０の傾斜面１２によって求心案内されて位置決め面Ｈ２で被支持部８の隅のアール部Ｒと実施例１ではガイドプレート１１の、実施例２では側壁１１０の傾斜面１２の基部のアール部ｒとの間により車両の前後左右方向を位置決めして実施例１では支持部４に、実施例２では支持部４０に支持される。
【００１６】
従って、キャブ２の下降動作ので被支持部８が実施例１では支持部４に対し、実施例２では支持部４０に対し位置決めされることにより被支持面９に開設されている第１ロックボルト穴１０が実施例１では支持面５に、実施例２では支持面５０に開設されている第２ロックボルト穴７と正しく一致されるので作業者はキャブ２の下降時や下降後の第１、第２ロックボルト穴１０、７の位置合わせの作業を省略してロアマウントゴム１９とロアワッシャ２０を貫通したロックボルト１４を第２ロックボルト穴７及び第１ロックボルト穴１０に容易に挿入してナット１６の締め付けによりキャブ２をシャシフレーム１上に固定することができる。
【００１７】
【発明の効果】
以上述べたように本発明によると、簡単な構造によってシャシフレーム側の支持部に対しキャブ側の被支持部をキャブの下降時に案内し、かつ支持部の支持面と被支持部の被支持面に開設されているマウント部材のロックボルトを貫通する第１及び第２ロックボルト穴が一致するよう位置決めするようにした構造であるから、キャブをシャシフレームに組み付ける際の作業者によるボルト穴合わせ作業を省略することができキャブの組み付け作業性を向上すると共に作業者の労力負担を軽減する。
【図面の簡単な説明】
【図１】固定式のキャブマウント部位を示す車両の平面図
【図２】本発明によるキャブマウント構造の実施例１を示す図１のＡ−Ａ断面図
【図３】本発明によるキャブマウント構造の実施例２を示す図１のＡ−Ａ断面図
【図４】従来のキャブマウント構造を示す図１のＡ−Ａ断面図
【図５】従来のキャブマウント構造の不具合を示す断面図
【符号の説明】
１シャシフレーム
２キャブ
３キャブマウント部
４支持部
５支持面
６側壁
７第２ロックボルト穴
８被支持部
９被支持面
１０第１ロックボルト穴
１１側壁プレート
１２傾斜面
１３マウント部材
１４ロックボルト
１５カラー
１６ナット
１７アッパマウントゴム
１８アッパワッシャ
１９ロアマウントゴム
２０ロアワッシャ
２１側壁
４０支持部
５０支持面
１１０側壁 [0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fixed cab mount structure in which a cab of a truck is supported on a chassis frame by a mount.
[0002]
[Prior art]
As shown in FIG. 1, the cab overtrack includes a fixed cab in which a cab 2 is coupled by a mount member at a cab mount portion 3 at a plurality of positions in front of the chassis frame 1. As shown in FIG. 4, the conventional fixed cab mount structure includes a support portion 4 having a support surface 5 having a convex shape by a side wall 6 on the chassis frame 1 side, and a concave shape by a side wall 21 on the cab 2 side. None A supported portion 8 having a supported surface 9 supported by the support surface 5 is formed, and second and first locks that pass through lock bolts of the mount member 13 are formed in the supported surface 5 and the supported surface 9. Bolt holes 7 and 10 are formed, and the supported surface 9 is supported and coupled to the support surface 5 via the mount member 13.
[0003]
[Problems to be solved by the invention]
When the cab 2 is assembled to the chassis frame 1, the cab 2 is lowered onto the chassis frame 1 by a hoist or the like. In this case not necessarily supported portion 8 with respect to the support portion 4 in the above conventional structure is always lowered to its normal position, as shown in Figure 5 when supporting displaced back and forth or left and right of the vehicle, the supporting surface 5 2 The first lock bolt hole 10 of the supported surface 9 is displaced from the lock bolt hole 7. Accordingly, when the first lock bolt hole 10 is displaced and supported, the cab 2 is slightly lifted so that the operator can move the cab 2 so that the first lock bolt hole 10 corresponds to the second lock bolt hole 7 of the support portion 5 . Troublesome assembling work such as re-lowering while guiding, or the operator carefully guiding the cab 2 from the beginning of the lowering is required.
[0004]
An object of the present invention is to provide a cab mount structure in which a supported portion of a cab is positioned and supported at a normal position of a supporting portion of a chassis frame with a simple structure.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a fixed cab mount structure in which a truck cab is supported on a chassis frame 1 by a mount member 13 as described in claim 1, A rectangular shape having rounded corners R with a supported surface 9 in which the first lock bolt hole 10 of the mount member 13 is formed by a side wall 21 having four sides parallel to the horizontal axis. A support surface 5 provided with a support 8 and having a second lock bolt hole 7 of the mount member 13 on the chassis frame 1 side, and an axis line in the front-rear and left-right directions of the vehicle centering on the second lock bolt hole 7 Parallel to the side wall 21 of each of the supported portions 8 and a side wall 6 of four sides having substantially the same side length B1 as the side length B2 of the supported portion 8. On the outer surface A guide plate 11 for guiding the side wall 21 of the holding portion 8 is fixed, and the guide plate 11 is formed with an inclined surface 12 inclined at the upper portion with a rounded portion r in the outer direction, and the support surface 5 below the inclined surface 12. A positioning surface H2 that guides the side wall 21 of the supported portion 8 with a plane perpendicular to the first support bolt 5. The guide plate 11 allows the first lock bolt hole 10 of the supported surface 9 to pass through the second lock bolt of the support surface 5. It is characterized in that it matches with the hole 7 .
[0006]
According to another aspect of the present invention for achieving the above object, there is provided a fixed cab mount structure in which a cab of a truck rack is supported on a chassis frame 1 by a mount member 13, and the vehicle is mounted on the cab side. R-shaped corners R are formed at the corners of a square shape having a supported surface 9 in which the first lock bolt hole 10 of the mount member 13 is formed by a side wall 21 having four sides parallel to the longitudinal and lateral axes. A support surface 50 in which the second lock bolt hole 7 of the mount member 13 is opened on the chassis frame 1 side, and the support surface 50 is centered on the second lock bolt hole 7. A concave and square support portion 40 formed with four side walls 110 having a side length B3 that is parallel to the longitudinal and lateral axes of the vehicle and slightly longer than the side length B2 of each side wall 21 of the supported portion 8. The side wall 110 of the support portion 40 is formed with an inclined surface 12 inclined at the upper portion with a rounded portion r in the outer direction, and the surface of the supported portion 8 is perpendicular to the support surface 50 below the inclined surface 12. A positioning surface H2 for guiding the side wall 21 is provided, and the first lock bolt hole 10 of the supported surface 9 is aligned with the second lock bolt hole 7 of the support surface 50 by the side wall 110 of the support portion 40. It is characterized by this.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a chassis frame, 2 is a cab fixed on the chassis frame 1, and 3 is a cab mount portion 3 at a plurality of locations in front of the chassis frame 1.
[0008]
[Example 1]
FIG. 2 shows Example 1 of the present invention. In FIG. 2, 2 is a cab. On the cab 2 side, a side wall 21 having four side edges parallel to the longitudinal axis of the vehicle in the front-rear and left-right directions is formed into a concave shape with a supported surface 9 and a rounded portion R is formed at the corner. A part 8 is provided. Reference numeral 1 denotes a chassis frame. On the side of the chassis frame 1, there is provided a square support portion 4 having a support shape 5 which is convex with four side walls 6 having substantially the same side length B 2 as the side length B 2 of each side wall 21 of the supported portion 8. A first lock bolt hole 10 that penetrates the lock bolt 14 of the mount member 13 is formed in the supported surface 9 , and a second lock bolt hole that penetrates the lock bolt 14 of the mount member 13 is formed in the support surface 5. 7 has been established.
[0009]
A guide plate 11 for guiding the supported portion 8 is fixed to the outer surface of each side wall 6 of the support portion 4 with the second lock bolt hole 7 as a center. The guide plate 11 is formed with an inclined surface 12 inclined at an upper portion with a rounded portion r on the upper side, and the side walls 21 of the supported portion 8 are in contact with the support surface 9 below the inclined surface 12 at a plane perpendicular to the support surface 9. A positioning surface H2 is provided.
[0010]
As an example of the guide plate 11, when the supported portion 8 is supported by the support portion 4 via the mount member 13, the inclined surface 12 has an inclination angle θ of 20 ° to 50 ° and is inclined from the support surface 9. The height H1 to the apex of the surface 12 is 50 mm, and the positioning surface H2 is 10 mm as a standard straight line portion between the rounded portion R of the supported portion 8 and the rounded portion r of the base of the inclined surface 12 of the guide plate 11. However, this is appropriately set to an appropriate value depending on the vehicle type. Further, it is desirable that the side wall 21 side length B2 of the supported surface 9 is smaller than the side length B1 of each side wall 6 of the support portion 4 to provide a gap t.
[0011]
The mount member 13 has a conventionally known structure. That is, the lock bolt 14, the collar 15, the nut 16, the upper mount rubber 17, the upper washer 18, the lower mount rubber 19, and the lower washer 20 are included.
[0012]
[Example 2]
FIG. 3 shows a second embodiment of the present invention. In FIG. 3, 2 is a cab. On the cab 2 side, a side wall 21 having four side edges parallel to the longitudinal axis of the vehicle in the front-rear and left-right directions is formed into a concave shape with a supported surface 9 and a rounded portion R is formed at the corner. The portion 8 is provided and the supported surface 9 has the same structure as that of the first embodiment in that a first lock bolt hole 10 is formed through the lock bolt 14 of the mount member 13 .
[0013]
In the second embodiment, the support surface 50 in which the second lock bolt hole 7 of the mount member 13 is opened on the chassis frame 1 side, and the front, rear, left and right of the vehicle centering on the second lock bolt hole 7 on the support surface 50. A support portion 40 having a concave shape formed with four side walls 110 having a side length B3 that is parallel to the direction axis and slightly larger than the side length B2 of each side wall 21 of the supported portion 8 , The side wall 110 is provided with an inclined surface 12 inclined at an upper portion with a rounded portion r on the upper side, and a positioning surface H2 for guiding the supported portion 8 with a surface perpendicular to the support surface 50 below the inclined surface 12. ing.
[0014]
As an example of the side wall 110, in the state where the supported portion 8 is supported by the support portion 40 via the mount member 13 as in the first embodiment, the inclination angle θ of the inclined surface 12 is 20 ° to 50 °. The height H1 from the surface 9 to the apex of the inclined surface 12 is 50 mm, and the positioning surface H2 is a linear portion between the rounded portion R at the corner of the supported portion 8 and the rounded portion r at the base of the inclined surface 12 of the side wall 110. Although 10 mm is standard, this is appropriately set to an appropriate value depending on the vehicle type. Further, the side wall 21 side length B2 of the supported surface 9 is preferably smaller than the inner side length B3 of the side wall 110 to provide a gap t.
[0015]
Since the present invention has the structure as described above, in both the first and second embodiments, the upper mount rubber 17 is set on the support surfaces 5 and 50 at the position of the second lock bolt hole 7 together with the upper washer 18 . In this state, the cab 2 is lowered onto the chassis frame 1 by a hoist or the like, so that the supported portion 8 is supported even if there is a slight deviation from the supporting portion 4 in the first embodiment and the supporting portion 40 in the second embodiment. The side wall 21 of the portion 8 is centered and guided by the guide plate 11 in the first embodiment and the inclined surface 12 of the side wall 110 in the second embodiment, and the corner portion R of the supported portion 8 at the positioning surface H2 and the guide in the first embodiment. of the plate 11, the positions the longitudinal and lateral directions of the vehicle in example 1, the supporting portion 4 by between rounded portion r of the base of the inclined surface 12 of the side wall 110 in example 2, example 2, the support portion 40 It is supported.
[0016]
Therefore, since the downward movement of the cab 2 relative to the supported portion 8 In Example 1, the support portion 4, the first lock bolt is opened in the supported surface 9 by being positioned with respect to the support portion 40 in Embodiment 2 The hole 10 is correctly aligned with the support surface 5 in the first embodiment and the second lock bolt hole 7 formed in the support surface 50 in the second embodiment, so that the operator can perform the first operation after the cab 2 is lowered or after the lowering . easily inserted locking bolt 14 which penetrates the second Rokkubo belt lower mount rubber 19 and Roawassha 20 is omitted working alignment of the holes 10, 7 to the second locking bolt hole 7 and the first locking bolt hole 10 Thus, the cab 2 can be fixed on the chassis frame 1 by tightening the nut 16.
[0017]
【The invention's effect】
As described above, according to the present invention, the supported portion on the cab side is guided when the cab is lowered with respect to the supporting portion on the chassis frame side with a simple structure, and the supporting surface of the supporting portion and the supported surface of the supported portion are supported. Since the first and second lock bolt holes that pass through the lock bolts of the mounting member established in the above are positioned so as to match, the bolt hole alignment work by the operator when assembling the cab to the chassis frame Can be omitted, and the workability of the cab can be improved and the labor burden of the operator can be reduced.
[Brief description of the drawings]
FIG. 1 is a plan view of a vehicle showing a fixed cab mount portion. FIG. 2 is a cross-sectional view taken along line AA of FIG. 1 showing a first embodiment of a cab mount structure according to the present invention. 1 is a cross-sectional view taken along the line AA in FIG. 1 showing a second embodiment of the present invention. FIG. 4 is a cross-sectional view taken along the line AA in FIG. 1 showing a conventional cab mount structure. Explanation of]
DESCRIPTION OF SYMBOLS 1 Chassis frame 2 Cab 3 Cab mount part 4 Support part 5 Support surface 6 Side wall 7 2nd lock bolt hole 8 Supported part 9 Supported surface 10 1st lock bolt hole 11 Side wall plate 12 Inclined surface 13 Mount member 14 Lock bolt 15 Collar 16 Nut 17 Upper mount rubber 18 Upper washer 19 Lower mount rubber 20 Lower washer 21 Side wall 40 Support section 50 Support surface
110 Side wall

Claims

A fixed cab mount structure in which a cab of a truck is supported on a chassis frame 1 by a mount member 13. The mount member has a concave shape by four side walls 21 parallel to the longitudinal axis of the vehicle on the cab side. And a supported portion 8 having a supported surface 9 in which 13 first lock bolt holes 10 are formed and having rounded corners R formed at the corners, and the second lock bolt of the mount member 13 on the chassis frame 1 side. The support surface 5 in which the hole 7 is opened, and the side length B2 of each side wall 21 of the supported portion 8 that is parallel to the longitudinal axis of the vehicle around the second lock bolt hole 7 and substantially parallel to the axis of the supported portion 8. A support portion 4 having a convex shape is formed by four side walls 6 having the same side length B1, and a guide plate 11 for guiding the side wall 21 of the supported portion 8 is fixed to the outer surface of each side wall 6 of the support portion 4. ,Previous The guide plate 11 is formed with an inclined surface 12 inclined at an upper portion with a rounded portion r in the outer direction, and is positioned below the inclined surface 12 to guide the side wall 21 of the supported portion 8 with a surface perpendicular to the support surface 5. A cab mount structure comprising a surface H2, and the guide plate 11 makes the first lock bolt hole 10 of the supported surface 9 coincide with the second lock bolt hole 7 of the support surface 5.

A fixed cab mount structure in which a cab of a truck is supported on a chassis frame 1 by a mount member 13. The mount member has a concave shape by four side walls 21 parallel to the longitudinal axis of the vehicle on the cab side. And a supported portion 8 having a supported surface 9 in which 13 first lock bolt holes 10 are formed and having rounded corners R formed at the corners, and the second lock bolt of the mount member 13 on the chassis frame 1 side. A support surface 50 in which a hole 7 is formed, and the support surface 50 is parallel to an axis in the front-rear and left-right directions of the vehicle centering on the second lock bolt hole 7, and is formed on each side wall 21 of the supported portion 8. The side wall 110 of the support part 40 is provided with a concave-shaped square-shaped support part 40 in which four side walls 110 having a side length B3 slightly larger than the side length B2 are formed. And a positioning surface H2 for guiding the side wall 21 of the supported portion 8 in a plane perpendicular to the supporting surface 50 below the inclined surface 12 is provided. A cab mount structure in which the first lock bolt hole 10 of the supported surface 9 is aligned with the second lock bolt hole 7 of the support surface 50 by the side wall 110.