CN115923622A

CN115923622A - Ventilation cushion for automobile seat

Info

Publication number: CN115923622A
Application number: CN202211549390.9A
Authority: CN
Inventors: 陈统钗
Original assignee: Zhejiang Tianhong Automobile Products Co ltd
Current assignee: Zhejiang Tianhong Automobile Products Co ltd
Priority date: 2022-12-05
Filing date: 2022-12-05
Publication date: 2023-04-07

Abstract

The application relates to a ventilation back cushion of an automobile seat, wherein a plurality of ventilation holes are formed in a back cushion body, a fan installation position is arranged in a region, located in the ventilation holes, of the back face of the back cushion body, the back cushion body comprises an edge portion, a back rest portion and a waist rest portion, the back rest portion and the waist rest portion are both located in a region surrounded by the edge portion, a plurality of flow guide grooves are longitudinally formed in the back rest portion, and a back rest ventilation region is formed between every two adjacent flow guide grooves; the waist rest part is transversely provided with at least one groove, and both ends of the groove are respectively provided with a waist rest ventilation area; a supporting bulge is arranged at the position, corresponding to the groove, of the back surface of the back cushion body, and the fan mounting position is located at the upper side position of the supporting bulge; the ventilation hole all sets up in the ventilation zone and the waist that lean against that correspond leans on the ventilation zone. The air outlet quantity of the back cushion is inconsistent and uneven to a great extent.

Description

Ventilation cushion for automobile seat

Technical Field

The application relates to the field of automobile seat cushions, in particular to a ventilation cushion of an automobile seat.

Background

The automobile is a common vehicle in the modern times, along with the gradual development of the times and the continuous improvement of the daily living standard of people, the automobile has more requirements on the driving comfort level of the automobile, and the automobile is required to have higher controllability and better comfort.

However, in the production process of the automobile, the automobile needs to be taught according to the use environment of each automobile type, if the training in comfort is inclined, the controllability of the automobile is partially sacrificed, and vice versa, especially for the training of SUVs and all-terrain vehicles, the sacrifice in comfort is relatively more.

The automobile seat is a main aspect of comfort for drivers and passengers, so that a plurality of seat cushions and back cushions for the automobile seat exist, the back cushions are common in daily life like breathable back cushions, in hot summer, the drivers and passengers are prone to sweat in the automobile, particularly, the back of the driver and the passengers can seriously affect the comfort due to the sweat, and the breathable back cushion can improve the breathability to a certain degree, so that the comfort of the drivers and the passengers is better.

For example, the Chinese patent publication No. CN203211145U of the ventilation back cushion for the automobile seat comprises a back cushion outer sleeve and a plug with a speed control device, wherein a back cushion main body and a back cushion front plate are arranged in the back cushion outer sleeve; fan mounting bins are arranged on two sides of the front lower end of the back cushion main body, and turbofan fans are arranged in the fan mounting bins; air outlet guide grooves are formed in the periphery of the fan mounting bin; the cushion front plate is arranged at the front end of the cushion main body, and an air outlet is arranged at the position, corresponding to the air outlet guide groove, on the cushion front plate.

With respect to the related art in the above, the inventors consider that: lean on after long-time by driver and crew, lead to the fan position too to press close to seat and driver and crew's health back, cause the air output to reduce, lead to the fan even because the air current volume is obstructed, burn out easily, and simultaneously, the air outlet is too scattering in the design, the air output difference that leads to every air outlet is great, the part air output far away from the fan is less, and stronger part air output is big, but plug up when leaning on after easily, consequently, it is relatively poor to cause holistic ventilation effect.

Also, for example, in a ventilation chair of CN2273137Y, a plurality of longitudinal ribs are protruded on the back of the back cushion to divide the back cushion into a plurality of ventilation slots, and a plurality of transverse ribs for fixing the longitudinal ribs are embedded at proper positions of the longitudinal ribs to prevent the occurrence of disorder phenomenon caused by shaking with human body; a reverse folding slot is dug on the upper surface of the back cushion to block the airflow from the ventilation slot of the back cushion and change the airflow direction.

With respect to the related art in the above, the inventors consider that: its ventilation groove essence is for indulging with a square big air outlet utilization, violently the air outlet of a plurality of rectangles is divided into to the vertical rib and the horizontal rib that set up, it is even can guarantee certain air output, but the regional air output that is close to the waist position is great relatively, and the amount of wind of the ventilation groove of upside will be very little, if use powerful fan, though can guarantee holistic air output, but can lead to the air output of waist bigger, and in the vehicle went, the air output of upside also can be neglected a lot, cause driver and crew's health to catch a cold discomfort easily.

Disclosure of Invention

In order to improve the inconsistent and inhomogeneous defect of cushion air output among the above-mentioned correlation technique, this application provides a ventilation cushion of car seat.

The application provides a ventilation cushion of car seat adopts following technical scheme:

a ventilation cushion of an automobile seat comprises a cushion body, wherein a plurality of ventilation holes are formed in the cushion body, a fan installation position is arranged in a region, located in the ventilation holes, of the back face of the cushion body, the cushion body comprises an edge portion, a backrest portion and a waist rest portion, the backrest portion and the waist rest portion are located in a region surrounded by the edge portion, a plurality of flow guide grooves are longitudinally formed in the backrest portion, and a backrest ventilation region is formed between every two adjacent flow guide grooves; the waist support part is transversely provided with at least one groove, and both ends of the groove are respectively provided with a waist support ventilation area; a supporting bulge is arranged at the position, corresponding to the groove, of the back surface of the back cushion body, and the fan mounting position is located at the upper side position of the supporting bulge; the ventilation hole all sets up in the ventilation zone and the waist that lean against that correspond leans on the ventilation zone.

Optionally, the diversion trench extends from the lower side position of the backrest part to the upper side position, and extends to the edge of the backrest part to be connected with the edge part.

Optionally, the backrest ventilation area is sequentially and respectively arranged from the middle to both sides as a first ventilation area, a second ventilation area, a third ventilation area and a fourth ventilation area, and the diversion trenches between the first ventilation area and the second ventilation area are extended upwards from the lower side position of the backrest part to the middle position and then inclined upwards towards the outside to form an arc-shaped diversion section; the diversion trenches between the second ventilation area and the third ventilation area extend upwards from the lower side position of the backrest part to the middle position and then incline upwards towards the outside to form an arc diversion section; the diversion trench between the third ventilation zone and the fourth ventilation zone extends from the lower side position of the backrest part to the upper side position and inclines outwards to form an arc diversion section.

Optionally, the widths of the diversion trenches between the first ventilation area and the second ventilation area are equal from bottom to top.

Optionally, the width of the diversion trench between the second ventilation area and the third ventilation area gradually increases from bottom to top.

Optionally, the width of the diversion trench between the third ventilation zone and the fourth ventilation zone is gradually increased from bottom to top.

Optionally, the width of the diversion trench between the first ventilation area and the second ventilation area is greater than the maximum width of the diversion trench between the second ventilation area and the third ventilation area; the width of the diversion trench between the first ventilation area and the second ventilation area is larger than or equal to the maximum width of the diversion trench between the third ventilation area and the fourth ventilation area.

Optionally, the vent holes of the first ventilation area and the fourth ventilation area are strip-shaped holes with equal width; three groups of vent holes of the first ventilation area are arranged from bottom to top, the lengths of the group of strip-shaped holes on the lower side are equal, the length of the group of strip-shaped holes in the middle is gradually increased from bottom to top, and the length of the group of strip-shaped holes on the upper side is gradually decreased from bottom to top; the minimum length of the strip-shaped holes in the middle group is greater than that of the strip-shaped holes in the lower group, and the maximum length of the strip-shaped holes in the upper group is greater than that of the strip-shaped holes in the upper group; the length of the strip-shaped hole of the fourth ventilation area is gradually reduced from bottom to top.

Optionally, the ventilation holes in the second ventilation area and the third ventilation area are circular holes, and the aperture of the ventilation hole in the second ventilation area and the aperture of the ventilation hole in the third ventilation area are gradually increased from bottom to top.

Optionally, the front of the edge portion is higher than the front of the back rest portion and the front of the lumbar support portion, transition sections are arranged at the positions, located on the left side and the right side of the lumbar support portion, of the edge portion, and the front of the transition sections is inclined towards the rear of the back cushion body to form the front of the transition sections to be connected with the front of the lumbar support portion.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the back cushion is provided with the supporting bulges, so that a larger ventilation space can be formed between the back surface of the back cushion and the seat, the ventilation space can still ensure enough ventilation even under the condition that a fan is not installed, and particularly, when the back cushion is extruded by a driver and passengers, the convection effect of air through the ventilation holes is stronger; the fan mounting position is arranged at the position close to the supporting bulge, so that the fan cannot be too close to the seat and the back of the body of a driver or an occupant even if the driver or the occupant leans against the seat, the problem of air flow reduction and air flow obstruction is improved to a great extent, and the ventilation effect is stronger, more remarkable and better; meanwhile, through setting up the guiding gutter, can be so that the air after being obstructed, can be better to the diffusion of edge part, the effectual ventilation effect that has improved can not cause the influence to air output and air flow moreover for the air output is more unanimous and even.

2. Through the setting to each ventilation zone and to the adjustment of the extending direction of guiding gutter for the flow direction of wind has obtained fine guide and overall arrangement, can be better with the flow direction guide of wind driver and passenger's back spine periphery, shoulder blade, rib, waist and the position of rib and waist both sides, make every position of perspiring easily in back can both reach good ventilation effect, better accord with ergonomic design.

3. Through the hole pattern design and the design of length, width size to the ventilation hole of each ventilation zone, every position of perspiring easily in matching driver and crew's back that can be better has further promoted ventilation effect.

4. Through setting up edge part and back of the body portion, the difference in height between the waist portion of leaning on, buffer when partly receiving the pressure has been reserved, can make driver and crew in the in-process of taking like this, can not block up the ventilation hole easily when leaning on after, the effect of ventilation has effectively been strengthened, make the circulation of air more smooth and easy, the wind through guiding gutter or other ventilation holes can both be even spread in the space that the difference in height formed, the defect that air output was suddenly little after the ventilation hole was blocked up has been improved to a greater extent, make every ventilation zone, the guiding gutter is both independent, can call for each other again supplementary.

Drawings

Fig. 1 is a schematic front view of an embodiment of the present application.

Fig. 2 is a schematic front structure diagram of an embodiment of the present application.

Fig. 3 is a schematic diagram of a back structure of an embodiment of the present application.

Fig. 4 is a partially enlarged schematic view of a portion a in fig. 2.

Fig. 5 is a schematic view of the structure of the ventilated cushion of the embodiment of the present application against the back of a human body.

Description of reference numerals: 1. a vent hole; 2. a fan mounting position; 3. an edge portion; 4. an arc-shaped flow guide section; 5. a transition section; 6. a support boss; 7. a groove; 8. a diversion trench; 9. reinforcing ribs; 10. an elastic support member; 11. a transition piece.

Detailed Description

The present application is described in further detail below with reference to figures 1-5.

The embodiment of the application discloses a ventilation cushion of an automobile seat. Referring to fig. 1 to 3, a plurality of vent holes 1 are formed in a cushion body, a fan installation position 2 is arranged in a region, located in the vent holes 1, of the back surface of the cushion body, the cushion body comprises an edge portion 3, a back rest portion and a lumbar rest portion, the edge portion 3 encloses a region with an opening at the lower side, and the back rest portion and the lumbar rest portion are both located in a region enclosed by the edge portion 3; referring to fig. 4, the front of edge portion 3 all is higher than the portion of leaning against, the front of the portion of leaning against on of waist, namely, edge portion 3 and the portion of leaning against, the difference in height between the portion of leaning against is made, in order to form step-like structure, buffer area when just so reserving a part and leaning against and pressing, can make the driver and crew at the in-process of taking, can not block up ventilation hole 1 easily during the back leaning against, the effect of effectively having strengthened the ventilation, make the circulation of air more smooth and easy, the wind that passes through guiding gutter 8 or other ventilation holes 1 can both be even spread in the space that the difference in height formed, the defect that air output is suddenly big and suddenly after ventilation hole 1 is blockked up has been improved to a greater extent, make every ventilation area, guiding gutter 8 is both independent, can call for each other auxiliarily.

The position that edge portion 3 is located the left and right both sides of waist rest portion is provided with changeover portion 5, and the front of changeover portion 5 is connected with the front of waist rest portion to cushion body rear slope setting formation changeover portion 5, and the design can make left edge portion 3 of body lower part can not be to driver and passenger's buttock long-time roof pressure when driving, has improved driver and passenger's comfort level like this.

In this embodiment, the backrest part is longitudinally provided with a plurality of flow guide grooves 8, the flow guide grooves 8 extend from the lower side position of the backrest part to the upper side position, and extend to the edge of the backrest part to be connected with the edge part 3, and the flow guide grooves 8 can enable air to better diffuse towards the edge part 3 after being blocked, so that the ventilation effect is effectively improved, the air outlet quantity and the air flow quantity cannot be influenced, and the air outlet quantity is more consistent and uniform; the back of the cushion body and the position corresponding to each diversion trench 8 bulge to the back of the cushion body to form a reinforcing rib 9, the reinforcing ribs 9 extend from the lower side position of the backrest part to the upper side position, and one end of the reinforcing rib 9 positioned at the upper side of the backrest part is not connected with the edge part 3; the fan mounting positions 2 are disposed on the reinforcing ribs 9 on the lower side of the backrest portion, in this embodiment, two positioning columns are disposed on two adjacent reinforcing ribs 9 in the middle at intervals, and the fan is mounted and fixed through the positioning columns on the two reinforcing ribs 9.

In the embodiment, a back-to-back ventilation area is formed between adjacent flow guide grooves 8, and the ventilation holes 1 are arranged in the corresponding back-to-back ventilation areas; the backrest ventilation area is sequentially and respectively arranged into a first ventilation area, a second ventilation area, a third ventilation area and a fourth ventilation area from the middle to two sides.

The diversion trench 8 between the first ventilation area and the second ventilation area extends upwards from the lower side position of the backrest part to the middle position and then inclines upwards towards the outer side to form an arc diversion section 4, and the width of the diversion trench 8 between the first ventilation area and the second ventilation area is equal from bottom to top; the diversion trench 8 between the second ventilation area and the third ventilation area extends upwards from the lower side position of the backrest part to the middle position and then inclines upwards towards the outer side to form an arc diversion section 4, and the width of the diversion trench 8 between the second ventilation area and the third ventilation area is gradually increased from bottom to top; the diversion trench 8 between the third ventilation zone and the fourth ventilation zone extends from the lower side position of the backrest part to the upper side position and inclines outwards to form an arc diversion section 4, and the width of the diversion trench 8 between the third ventilation zone and the fourth ventilation zone is gradually increased from bottom to top.

In the above, the width of the diversion trench 8 between the first ventilation area and the second ventilation area is greater than the maximum width of the diversion trench 8 between the second ventilation area and the third ventilation area; the width of the diversion trench 8 between the first ventilation zone and the second ventilation zone is greater than or equal to the maximum width of the diversion trench 8 between the third ventilation zone and the fourth ventilation zone.

In this embodiment, the vent holes 1 of the first vent area and the fourth vent area are strip-shaped holes with equal width; three groups of vent holes 1 in the first ventilation area are arranged from bottom to top, the lengths of the group of strip-shaped holes on the lower side are equal, the length of the group of strip-shaped holes in the middle is gradually increased from bottom to top, and the length of the group of strip-shaped holes on the upper side is gradually decreased from bottom to top; the minimum length of the strip-shaped holes in the middle group is greater than that of the strip-shaped holes in the lower group, and the maximum length of the strip-shaped holes in the upper group; the length of the strip-shaped hole of the fourth ventilation area is gradually reduced from bottom to top. Simultaneously, the ventilation hole 1 in second ventilation district and third ventilation district is the circular port, and the ventilation hole 1 in second ventilation district and third ventilation district's aperture all increases by supreme crescent down.

In this embodiment, the waist leans on the portion transversely to be provided with at least one recess 7, and the both ends of recess 7 are provided with the waist respectively and lean on the ventilation zone, and ventilation hole 1 sets up in the waist that corresponds and leans on the ventilation zone, and the design can make the air be behind the hindrance, can be better to the diffusion of edge portion 3, the effectual ventilation effect that has improved, recess 7 in addition when increasing the ventilation effect, can also reduce manufacturing cost to a certain extent, the saving that manufacturing material also can be better.

In the embodiment, the back surface of the cushion body is provided with the supporting bulge 6 at a position corresponding to the groove 7, so that a large ventilation space can be formed between the back surface of the cushion and the seat, the ventilation space can still ensure enough ventilation even under the condition that a fan is not installed, and particularly, when the cushion is extruded by a driver and an occupant, the convection effect of air through the ventilation hole is stronger; the fan installation position 2 is positioned at the upper side of the supporting bulge 6, and if a fan is installed on the fan installation position, the ventilation effect is stronger, more remarkable and better; in the embodiment, two grooves 7 are provided, and two supporting protrusions 6 are also provided at intervals correspondingly; can be so that the fan installation back, more can be close to the support protrusion 6, with fan installation position 2 setting in the position department that is close to the support protrusion 6, driver and crew can not lead to the fan position too to press close to seat and driver and crew's health back at the in-process that leans on after, and to a great extent has improved the air output and has reduced the obstructed problem of air flow.

In order to ensure that the back cushion is not easy to shift caused by the adjustment of the sitting posture of a driver, the lower end of the back cushion body is connected with an elastic supporting piece 10 which is arranged towards the rear side direction and inclines downwards, and the elastic supporting piece 10 is connected with the lower end of the back cushion body through an arc-shaped transition connecting piece 11. In this embodiment, the left and right side edges of the elastic supporting member 10 gradually contract and incline towards the middle towards the rear side direction, so that the elastic supporting member can be well inserted into the gap of the car seat, and the elastic supporting performance of the transition connecting member 11 and the area of the elastic supporting member 10 close to the transition connecting member 11 is not changed, and meanwhile, the waste of materials is effectively reduced, and the cost is saved.

The design principle of the embodiment is as follows: through the setting to each ventilation zone and to the adjustment of the extending direction of guiding gutter 8 for the flow direction of wind has obtained fine guide and overall arrangement, can be better with the flow direction guide of wind driver and passenger's back the position of backbone periphery, scapula, rib, waist and rib and waist both sides, make every position of perspiring easily in the back can both reach good ventilation effect, better accord with ergonomic design. Referring to fig. 5, generally, when the back of a human body is in a hot environment, the positions with more sweating are the positions between the cervical vertebrae and the waist and the middle positions of the waist, particularly the positions close to the middle positions of the cervical vertebrae are more, next, the positions near the shoulder blades and the positions near the ribs, including the positions under the armpits, according to the design scheme in the embodiment of the application, the arrangement and the size of the ventilation holes 1 are designed according to the sweating condition of each position, if the first ventilation area corresponds to the positions between the cervical vertebrae and the waist and the middle positions of the waist, the second ventilation area corresponds to the positions near the shoulder blades, during ventilation, the shoulder parts can also blow a small amount of air, the third ventilation area can blow the positions near the ribs and the positions under the armpits, meanwhile, due to the arc-shaped design of the cushion body, the prothorax part can also blow a small amount of air, the fourth ventilation area can blow air to the positions on two sides of the waist, and blow a small amount of air to the abdomen of the human body, and in addition, the ventilation holes 1 on the two sides of the waist near the ventilation area can also blow the waist, and assist the abdomen of the human body at the same time.

In addition, the hole pattern design and the design of the length and the width of the vent holes 1 of each ventilation area are small holes with relatively small hole areas, such as the lower side vent holes of the first ventilation area, the second ventilation area and the third ventilation area, the design can effectively restrict the air quantity of the positions close to the waist and the position close to the waist from being overlarge, the air quantity can be moderately blown out, the positions far away from the parts, such as the fourth ventilation area and the waist leaning ventilation area, and the middle side vent holes and the upper side vent holes of the first ventilation area, the second ventilation area and the third ventilation area are relatively large, so that the air quantity can be ensured even if the air quantity is conveyed a little far away, the uniformity of the air quantity of each part is ensured on the whole, the phenomenon that the air quantity is suddenly reduced is avoided, the condition that the back part is too cold due to uneven air quantity, the cold air cannot be blown to the individual part or the air quantity is extremely small is avoided, therefore, the hole pattern shape and the hole size design can better match each part of the driver and the driver, which is easy to sweat on the back, the uniformity is high, and the further can have the improvement effect.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. The utility model provides a ventilation cushion of car seat, includes the cushion body, is provided with a plurality of ventilation holes (1) on the cushion body, and the back of cushion body is provided with fan installation position (2), its characterized in that in the region that is located ventilation hole (1): the back cushion body comprises an edge part (3), a backrest part and a waist part, wherein the backrest part and the waist part are both positioned in an area surrounded by the edge part (3), the backrest part is longitudinally provided with a plurality of flow guide grooves (8), and a backrest ventilation area is formed between the adjacent flow guide grooves (8); the waist rest part is transversely provided with at least one groove (7), and both ends of the groove (7) are respectively provided with a waist rest ventilation area; a supporting bulge (6) is arranged at the position, corresponding to the groove (7), of the back surface of the back cushion body, and the fan mounting position (2) is located at the upper side position of the supporting bulge (6); ventilation hole (1) all set up in the ventilation zone is leaned on to the back that corresponds and the ventilation zone is leaned on to waist.

2. A ventilated cushion for a vehicle seat as set forth in claim 1, wherein: the diversion trench (8) extends from the lower side position of the backrest part to the upper side position and extends to the edge of the backrest part to be connected with the edge part (3).

3. A ventilated cushion for a vehicle seat as set forth in claim 2, wherein: the backrest ventilation area is sequentially and respectively provided with a first ventilation area, a second ventilation area, a third ventilation area and a fourth ventilation area from the middle to two sides, and a diversion trench (8) between the first ventilation area and the second ventilation area is upwards extended to the middle from the lower side position of the backrest part and then is outwards inclined upwards to form an arc diversion section (4); the diversion trenches (8) between the second ventilation area and the third ventilation area extend upwards to the middle position from the lower side position of the backrest part and then incline upwards towards the outside to form an arc diversion section (4); the diversion trench (8) between the third ventilation zone and the fourth ventilation zone extends from the lower side position of the backrest part to the upper side position and inclines outwards to form an arc diversion section (4).

4. A ventilated cushion for a vehicle seat as claimed in claim 3, wherein: the widths of the flow guide grooves (8) between the first ventilation area and the second ventilation area are equal from bottom to top.

5. A ventilated cushion for a vehicle seat as claimed in claim 3, wherein: the width of the diversion trench (8) between the second ventilation zone and the third ventilation zone is gradually increased from bottom to top.

6. A ventilated cushion for a vehicle seat as set forth in claim 3, wherein: the width of the flow guide groove (8) between the third ventilation area and the fourth ventilation area is gradually increased from bottom to top.

7. A ventilated back cushion for vehicle seats according to any one of claims 3 to 6, wherein: the width of the diversion trench (8) between the first ventilation area and the second ventilation area is larger than the maximum width of the diversion trench (8) between the second ventilation area and the third ventilation area; the width of the diversion trench (8) between the first ventilation area and the second ventilation area is larger than or equal to the maximum width of the diversion trench (8) between the third ventilation area and the fourth ventilation area.

8. A ventilated back cushion for vehicle seats according to any one of claims 2 to 6, wherein: the vent holes (1) of the first ventilation area and the fourth ventilation area are strip-shaped holes with equal width; three groups of vent holes (1) of the first ventilation area are arranged from bottom to top, the lengths of the strip-shaped holes on the lower side are equal, the length of the strip-shaped hole in the middle is gradually increased from bottom to top, and the length of the strip-shaped hole on the upper side is gradually decreased from bottom to top; the minimum length of the strip-shaped holes in the middle group is greater than that of the strip-shaped holes in the lower group, and the maximum length of the strip-shaped holes in the upper group; the length of the strip-shaped hole of the fourth ventilation area is gradually reduced from bottom to top.

9. A ventilated back cushion for vehicle seats according to any one of claims 2 to 6, wherein: the ventilation holes (1) of the second ventilation area and the third ventilation area are circular holes, and the hole diameters of the ventilation holes (1) of the second ventilation area and the third ventilation area are gradually increased from bottom to top.

10. A ventilated back cushion for vehicle seats according to any one of claims 1 to 6, wherein: the front of edge portion (3) all is higher than the front that leans on portion, waist to lean on the portion, and edge portion (3) are located the position that the waist leaned on the left and right both sides and are provided with changeover portion (5), and the front of changeover portion (5) sets up to cushion body rear slope and forms the front of changeover portion (5) and is connected with the front that the waist leaned on the portion.