Sliding window

Abstract: A sliding window is provided with a roof (100) of a vehicle body. The window includes a frame (13) fitted to an opening formed with the roof (100). The frame (13) is made of a hard material that has a linear expansion coefficient substantially equal to that of the vehicle body. A plate (11) that made of a hard resin material is fitted to the frame (13). A molding (12) that is made of a soft material is interposed between the plate (11) and the frame (13). The molding (12) has a flexible portion (120) so as to absorb a deformation of the plate (11) due to changes of temperature.

Description: The present invention relates to a window for selectively opening and closing an opening of a vehicle roof according to the preamble of claim 1 and more particularly to sliding windows that are made of a synthetic resin and provided in vehicle roofs. A roof of an automobile may be provided with a sliding window. The window is opened to draw fresh air into the passenger compartment. A typical sliding window 9 is illustrated in Fig. 7. As shown in Fig. 8(a), the window 9 is fit into an opening in the roof 99 of a vehicle. The window 9 may be lowered with respect to the roof 99 and then moved along a pair of guide rails 97 to open the roof 99, as shown in Fig. 8(b). As shown in Figs. 7 and 9, the window 9 includes an inorganic glass 91, a molding 92, and a weather strip 93. The molding 92 encompasses the glass 91. The weather strip 93 encompasses the outer side of the molding 92 to seal the space between the window 9 and the roof 99. The molding 92 is made of a relatively hard resin while the weather strip 93 is made of a soft rubber. As shown in Fig. 9, a washer 951 and a fastener 952 is attached to the bottom surface of the molding 92 near each side of the glass 91. An elbow-like bracket 962 is held by the fastener 952. A shaft 961, which supports a roller 96, is coupled to the bracket 962. The roller 96 rolls along the rail 97. This simple sliding structure enables opening and closing of the window 9. During recent years, it has become preferable to use a transparent synthetic resin plate for the sliding window instead of the inorganic glass. A resin plate is lighter and has a better appearance than inorganic glass. When employing a resin plate, it is preferable that major changes are not required in the above sliding structure. In other words, it is preferable that a sliding window employing a resin plate have the same highly reliable structure as the prior art sliding window in which the structure enables sealing of the space between the window and the roof and also enables opening and closing of the window. However, the linear expansion coefficient of a synthetic resin is greater than that of an inorganic glass. When the vehicle travels, the outdoor temperature causes expansion or contraction of the resin plate. The deformation of the glass results in degradation of the sealing ability between the sliding window 9 and the roof 99. This may degrade the comfortable environment in the passenger compartment. A generic window for selectively opening and closing an opening that is provided within a roof of a vehicle body is known from US-A-4 881 773. The window includes a separating plate for separating an interior from an exterior, a frame supporting the separating plate and a molding interposed between the separating plate and the frame. The frame is made of a hard material having a linear expansion coefficient substantially equal to that of the roof. The separating plate is made of a hard resin material. The molding has a flexible portion to absorb a deformation of the separating plate based on changes of temperature. A further window for a vehicle roof, according to the preamble of claim 1, is known from EP-A-0 662 401. The window includes a separating plate for separating an interior from an exterior, a frame supporting the separating plate and a molding interposed between an outer periphery of the separating plate and the frame. The molding has a thinner portion serving as a flexible portion which undergoes a bending stress if separating plates of different dimensions are installed. It is an object of the present invention to further develop a window according to the preamble of claim 1. According to the invention, this object is achieved by a window having the features of claim 1. Advantageous further developments are set out in the dependent claims. According to the invention, a light sliding window is provided which has a superior appearance and a high reliability. The invention, together with object and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which: Fig. 1 is a cross-sectional view schematically showing the structure of a sliding window according to a first embodiment of the present invention; Fig. 2 is a cross-sectional view schematically showing the sliding window in a low-temperature state; Fig. 3 is a cross-sectional view schematically showing the sliding window in a high-temperature state; Fig. 4 is a schematic view showing a testing fixture; Fig. 5 is a cross-sectional view schematically showing the structure of a comparative product; Fig. 6 is a graph illustrating vertical deformation; Fig. 7 is a plan view showing a prior art sliding window; Fig. 8(a) is a diagrammatic drawing illustrating the prior art sliding window in a closed state; Fig. 8(b) is a diagrammatic drawing illustrating the prior art sliding window in an opened state; and Fig. 9 is a cross-sectional view schematically showing the structure of a prior art sliding window. A first embodiment of a resin sliding window according to the present invention will hereafter be described with reference to Figs. 1 to 6. As shown in Figs. 1 to 3, a sliding window 1 includes a transparent synthetic resin plate 11, a molding 12 arranged encompassing the plate 11, and a frame 13 arranged encompassing the molding 12. The sliding window 1 is provided in a roof 100 of an automobile. In this embodiment, the resin plate 11 is made of a transparent polycarbonate (PC) resin and formed through injection molding. However, the material of the resin plate 11 is not limited to PC. Other transparent resins such as polymethylmethacrylate (PMMA) may also be employed as the material of the plate 11. If the transparency of the sliding window is not required, resins that are not transparent may also be used as the material of the plate 11. In this embodiment, the molding 12 is made of flexible poly vinyl chloride (PVC) and is insert molded around the plate 11. However, the material of the molding 12 is not limited to PVC. Other flexible resin or rubber materials such as ethylene-propylene-diene terpolymer (EPDM) or olefine thermoplastic elastomer (TPO) may also be used. It is preferable that the rubber hardness of the molding 12 be within the range of 20 to 80. The rubber hardness of PVC employed in this embodiment is approximately 40. The molding 12 has a thickness T. A thin section 120 is defined in the molding 12. The thickness of the thin section 120 is less than the thickness T of the molding 12. In this embodiment, the frame 13 is made of sheet moulding compound (SMC), which is a reinforced plastic. The linear expansion coefficient of SMC is almost the same as that of steel. That is, the linear expansion coefficient of the frame 13, which is 1.8×10 -5 cm/cm/°C, is slightly greater than that of steel (1.17×10 -5 cm/cm/°C) but much smaller than that of the resin plate 11 (PC, 7×10 -5 cm/cm/°C). The material of the frame 13 is not limited to SMC. However, it is preferable that the frame 13 have a linear expansion coefficient of 1.8×10 -5 cm/cm/°C or less and be made of a material selected from a group consisting of steel, aluminum, reinforced plastic, or the like. This sufficiently satisfies the requirements of the linear expansion coefficient relationship described above. Reinforced plastics such as bulk molding compound (BMC) and fiber reinforced plastic (FRP) may be used as the material of the frame 13. As shown in Fig. 1, the frame 13 has an L-shaped cross-section. This enables the inner walls, outer walls, and bottom of the frame 13 to be effectively used. The molding 12 is adhered to the frame 13 by a butyl adhering agent. As shown in Fig. 1, a weather strip 4 is adhered around the frame 13. The weather strip 4 may also be formed integrally with and from the same material as the molding 12. In the same manner as the prior art, a washer 101 and a fastener 102 are attached to the bottom surface of the frame 13. A bracket 103 is held by the fastener 102. A shaft 104, which supports a roller 6, is coupled to the bracket 103. The roller 6 rolls along a guide rail 7 and enables the sliding window 1 to move with respect to the rail 7. The sliding window 1 according to the present invention is provided with the resin plate 11 encompassed by the molding 12 in the frame 13. Accordingly, the dimensions of the sliding window 1 are determined by the dimensions of the frame 13. In addition, the molding 12 is provided with the thin section 120 located between the resin plate 11 and the frame 13. The thin section 120 is flexible in comparison with other parts of the molding 12. Therefore, the thin section 120 expands when low temperature causes contraction of the plate 11 as shown in Fig. 2. The contraction of the plate 11 is absorbed by the thin section 120. The thin section 120 contracts when high temperature causes expansion of the plate 11 as shown in Fig. 3. The expansion of the plate 11 is absorbed by the thin section 120. Accordingly, the thin section 120 of the molding 12 prevents changes in the dimensions of the frame 13 when the plate 11 is deformed by different temperatures. This, in turn, prevents deformation of the entire sliding window 1. The linear expansion coefficient of the frame 13 is almost the same as that of steel. Thus, the difference between the linear expansion coefficient of the frame 13 and that of the steel vehicle body including the roof 100 is small. Accordingly, the space defined between the periphery of the sliding window 1 and the roof 100, where the window 1 is fit into, remains substantially the same regardless of changes in the temperature. In addition, the space between the sliding window 1 and the roof 100 is kept sealed by the weather strip 4. The vertical and lateral linear deformation of the sliding window 1 was measured by a testing fixture 8 illustrated in Fig. 4. A thermoplastic elastomer (RABALON, registered trademark of Mitsubishi Kagaku Kabushiki Kaisha) was used for the molding 12. The vertical and lateral linear deformation of a comparative (prior art) product was also measured to compare data. The comparative product employed the same resin plate 11 as the sliding window 1 according to the present invention. Thus, each plate 11 is made of the same material. However, as shown in Fig. 5, a molding 122 of the comparative product is not provided with a thin section and is not encompassed by a frame. Thus, the molding 122 is directly connected to the weather strip 4. Polyamide 66, which is a well-known material, was used as the material of the molding 122. The remaining structure of the comparative product is the same as the structure of the sliding window 1 of the present invention. As shown in Fig. 4, the testing fixture 8 includes a steel setting device 81, by which the sliding window 1 and the comparative product were held, a vertical reference bar 82, which indicates a vertical reference point (first reference point), and a lateral reference bar 83, which indicates a lateral reference point (second reference point). The sliding window that was to be tested was set on the setting device 81 so as to simulate conditions during actual usage. The fasteners 102 of each sliding window were fixed to the setting device 81 when vertical linear deformation was measured and slidably connected to the device when linear lateral deformation was measured. After each sliding window was set on the setting device 81, the vertical distance H1 between the first reference point and the sliding window and the lateral distance W1 between the second reference point and the sliding window was measured at room temperature (18 degrees Celsius). The vertical distance H2 between the first reference point and the sliding window and the lateral distance W2 between the second reference point and the sliding window was then measured at a high temperature (90 degrees Celsius). The vertical and lateral linear deformations ΔH, ΔW obtained from the difference between the two temperature conditions were calculated as follows: H2-H1=ΔH, W2-W1=ΔW Fig. 6 illustrates the results of the vertical linear deformation ΔH (mm). The lateral axis shows the measured subject while the vertical axis shows the vertical linear deformation ΔH. It is evident from the graph that the vertical deformation of the sliding window according to the present invention was about half of that of the comparative product. From this result, it may be understood that providing a thin section in the molding and using a flexible material for the molding sufficiently reduces vertical deformation. The lateral deformation ΔW of the sliding window according to the present invention was 0.3 mm while the lateral deformation ΔW of the comparative product was 1.2 mm. From this result, it is apparent that the lateral linear deformation ΔW of the sliding window according to the present invention was drastically reduced in comparison with the comparative product representing the prior art sliding window. It is apparent that the molding 12, which is made of a flexible material and is provided with the thin section 120, absorbs the deformation of the resin plate 2. In addition, the employment of a frame having a low linear expansion coefficient sufficiently suppresses deformation of the sliding window 1. The effects of the hardness of the molding 12 employed in the sliding window of the present invention was also evaluated. As shown in table 1, six types of moldings, each having a different rubber hardness, were evaluated. Among these evaluation products, E1, E, E3 represent the moldings 12 having a satisfactory rubber hardness. The rubber harndesses of E1, E2, E3 are 20, 50, 80, respectively. The products outside the satisfactory hardness range are represented by C2, C3, C4. The rubber hardness of C2 is below 10 while that of C3 is 100. The rubber hardness of C4 exceeds 100. Evaluation Product C2 E1 E2 E3 C3 C4 Shore Hardness Below 10 20 50 80 100 Over 100 Moldability Δ ○ ○ ○ ○ ○ Strength Δ ○ ○ ○ ○ ○ Absorption Effect ○ ○ ○ ○ ▵ × The evaluated items were moldability, strength, and absorption effect. Moldability was evaluated by judging the efficiency when filling a mold to insert mold the molding 12 about the resin plate 11 and by judging how simple it was to release the mold after completion of the molding. Strength was evaluated by judging whether damage was inflicted on the molding 12 or whether the molding 12 fell off from the resin plate during actual usage of the sliding window. Absorption effect was evaluated by judging whether the thin section 120 of the molding 12 effectively absorbed the expansion and contraction of the glass. Each molding 12 was evaluated as good (O), satisfactory (Δ), and poor (X). As evident from table 1, the moldability and strength of the molding becomes slightly inferior when the rubber hardness is lower than 10. The absorption effect of the molding 12 is lowered when the shore hardness is 100 or greater. Accordingly, the advantages of the present invention are further ensured by maintaining the shore hardness of the molding within the range of 20 to 80. Although only one embodiment of the present invention has been described herein, it should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the scope of the invention defined in the appended claims. Particularly, it should be understood that the above embodiment may be modified as described below. Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.

Claims: A window for selectively opening and closing an opening that is provided within a roof (100) of a vehicle body, said window including a separating plate (11) for separating an interior from an exterior, a frame (13) supporting said separating plate (11) and a molding (12) interposed between the outer periphery of said separating plate (11) and said frame (13), wherein said frame (13) is made of a hard material having a linear expansion coefficient substantially equal to that of said roof (100), said separating plate (11) is made of a hard resin material and said molding (12) has a thinner portion (120) serving as a flexible portion to absorb a deformation of said separating plate (11) based on changes of temperature, characterized in that said window is formed as a sliding window (1), wherein the plane defined by the exterior side of said separating plate (11) passes through the whole extent of said thinner portion (120). A sliding window according to claim 1, characterized in that said molding (12) is adhered to the frame (13), wherein for compensating for an expansion of said separating plate (11) said thinner portion (120) is permitted to bulge toward said frame (13). A sliding window according to claim 1, characterized in that said separating plate (11) has an outer edge, wherein said flexible portion (120) is disposed between said frame (13) and said outer edge. A sliding window according to any of the preceding claims, characterized in that said separating plate (11) is made of a material having a lineal expansion coefficient larger than that of said frame (13). A sliding window according to any of the preceding claims, characterized by a weather strip (4) made of a rubber material and disposed between an inner edge of the opening and said frame (13). A sliding window according to any of the preceding claims, characterized in that said frame (13) has an elbow-like shape in cross section. A sliding window according to any of the preceding claims, characterized in that said frame (13) is made of a material selected from the group consisting of steel, aluminum and reinforced plastic. A sliding window according to any of the preceding claims, characterized in that said separating pate (11) is made of a material selected from the group consisting of polymethylmethacrylate and polycarbonate. A sliding window according to any of the preceding claims, characterized in that said molding (12) is made of either soft rubber or soft resin both having a rubber hardness within the range of 20 to 80. A sliding window according to any of the preceding claims, characterized in that said molding (12) is made of a material selected from the group consisting of poly vinyl chloride, ethylene-proylene-diene terpolymer, and olefine thermoplastic elastomer. A sliding window according to any of claims 6 to 10, characterized by a mechanism disposed on a lower surface of said frame (13) for selectively opening and closing the window. A sliding window according to any of claims 7 to 11, characterized in that said separating plate (11) is made of transparent resin.

Inventors: KATO YOSHIFUMI, NISHIO AKITERU, KATO, YOSHIFUMI, NISHIO, AKITERU
Applicants: KK, KABUSHIKI KAISHA
Application year: 1996
Main classification: B60J10
IPC codes: B60J7, B60J10