Ceramic mold structure

By designing the wavy base surface and bent fitting surface structure of the ceramic mold, combined with the tightening method of the cloth strap, the green deformation and appearance problems of the ceramic product after grouting are solved, and the high precision and aesthetic effect of the product is achieved.

CN222858334UActive Publication Date: 2025-05-13HUIDONG JINSHAN CERAMICS CO LTD
View PDF 0 Cites 0 Cited by

Patent Information

Application Number
CN202421775879.2
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-07-24
Publication Date
2025-05-13
Estimated Expiration
2034-07-24

AI Technical Summary

Technical Problem

After grouting, the upper side of the product green body is severely deformed and does not meet the qualified standards. The lines on the peripheral side are not straight, and corrugated defects appear, which affects the appearance of the product.

Method used

A ceramic mold structure is designed, including the upper module, the bottom module, the left module, the right module, the front module and the rear module. The upper surface of the bottom module is a wavy base surface, and the joint surface between the modules is a bent fitting surface. It is tightened by multiple cloth straps to improve sealing performance.

Benefits of technology

It effectively avoids deformation problems on the upper and peripheral sides of the green body of the product, ensures that the product has beautiful appearance and size meets the requirements, improves the product's accuracy and sealing performance, and reduces production costs.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN222858334U_ABST
    Figure CN222858334U_ABST
Patent Text Reader

Abstract

The utility model relates to a ceramic mold structure which comprises an upper mold block, a bottom mold block, a left mold block, a right mold block, a front mold block and a rear mold block, and a ceramic green body containing cavity is defined by the upper mold block, the bottom mold block, the left mold block, the right mold block, the front mold block and the rear mold block. The upper surface of the bottom module is a wavy base surface, wavy joint surfaces matched with the wavy base surface are arranged on the lower sides of the left module, the right module, the front module and the rear module, joint surfaces among the left module, the right module, the front module and the rear module are bent joint surfaces, and a first positioning mechanism is arranged between the front module and the front sides of the left module and the right module; second positioning mechanisms are arranged between the rear module and the rear sides of the left module and the right module, third positioning mechanisms are arranged between the bottom module and the lower sides of the left module and the right module, fourth positioning mechanisms are arranged between the upper module and the upper sides of the left module and the right module, and a grouting opening is formed in the middle of the upper module. The die is simple, reasonable and practical in design and low in cost, and the production efficiency and the product percent of pass are improved.
Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] The utility model relates to the technical field of ceramic product manufacturing, in particular to a ceramic mould structure. Background Art

[0002] The general ceramic product molding process is: the raw materials are molded through a gypsum or resin mold by low-pressure quick discharge or high-pressure grouting, etc. → drying → glazing → firing → assembly → packaging. Each process must be fully inspected or tested. Among them, the grouting molding method is to make a slurry with certain fluidity and suspension properties by temperature and plasticizer, and then inject it into the model to solidify and shape. Figure 1 As shown, our company has a book combination ceramic product. During the sample trial production, the following defects in the grouting molding mold design occurred:

[0003] (1) Due to the large height difference on the upper side of the product, the upper side of the green product solidified after grouting is severely deformed and fails to meet the qualified standards;

[0004] (2) Due to the unreasonable structural design of the mold blocks, the lines around the green body of the product solidified after grouting are not straight and corrugated defects appear, affecting the appearance of the product.

[0005] In order to overcome these defects, this solution proposes a ceramic mold structure. Utility Model Content

[0006] The invention of the utility model aims to solve the problem that the existing grouting forming mold has the problem that the upper side of the green body of the product after grouting and curing is severely deformed and fails to meet the qualified standards, and the peripheral lines of the green body of the product are not straight and have corrugated defects, which affects the appearance of the product. The specific solution is as follows:

[0007] A ceramic mold structure includes an upper module, a bottom module, a left module, a right module, a front module, and a rear module arranged between the upper module and the bottom module, wherein the lower side of the upper module and the upper side of the bottom module and the inner sides of the left module, the right module, the front module, and the rear module together form a ceramic green body accommodating cavity. The upper surface of the bottom module is a wavy base surface, and the lower sides of the left module, the right module, the front module, and the rear module are respectively provided with wavy connecting surfaces matching the wavy base surface, the upper sides of the left module, the right module, the front module, and the rear module are located in the same plane, and the joint surfaces between the left module, the right module, the front module, and the rear module are bent-shaped fitting surfaces, a first positioning mechanism is provided between the front side of the front module and the front sides of the left and right modules, a second positioning mechanism is provided between the rear side of the rear module and the rear sides of the left and right modules, and the bottom module A third positioning mechanism is provided between the left and right sides and the lower sides of the left module and the right module, a fourth positioning mechanism is provided between the left and right sides of the upper module and the upper sides of the left module and the right module, a grouting port leading to the ceramic green body accommodating cavity is provided in the middle of the upper module, a plurality of cloth straps are used to tighten horizontally along the periphery of the left module, the front module, the right module and the rear module, a plurality of cloth straps are used to tighten longitudinally along the periphery of the upper module, the front module, the bottom module and the rear module, and a plurality of cloth straps are used to tighten longitudinally along the periphery of the upper module, the left module, the bottom module and the right module.

[0008] Furthermore, a left boss is provided on the inner surface of the left module, and the upper and lower sides of the left boss are chamfered. The bent fitting surface of the left module includes a first bending surface on the front and rear sides of the left boss and the inner surface of the left module connected to the first bending surface, and a boss is provided on the inner side of the left boss.

[0009] Furthermore, a right boss is provided on the inner surface of the right module, the upper and lower sides of the right boss are chamfered, and the bent fitting surface of the right module includes a second bent surface on the front and rear sides of the right boss and the inner surface of the right module connected to the second bent surface.

[0010] Furthermore, the inner surface of the front module is a plurality of arc-shaped surfaces vertically connected in sequence, and the bent fitting surface of the front module includes side surfaces on the left and right sides of the front module and a third bent surface connected to the side surfaces.

[0011] Furthermore, the inner surface of the rear module is a plurality of corrugated tooth surfaces vertically connected in sequence, and the bent fitting surface of the rear module includes side surfaces on the left and right sides of the rear module and a fourth bent surface connected to the side surfaces.

[0012] Furthermore, the first positioning mechanism includes a first groove arranged on the left and right sides of the front side of the front module, a first protrusion arranged on the front side of the left module and protruding to the right, and a first protrusion arranged on the front side of the right module and protruding to the left, and the first groove matches the first protrusion.

[0013] Furthermore, the second positioning mechanism includes a second groove arranged on the left rear side of the rear module, a third groove arranged on the right rear side of the rear module, a second protrusion arranged on the rear side of the left module and protruding to the right, and a third protrusion arranged on the rear side of the right module and protruding to the left, the second groove matches the second protrusion, and the third groove matches the third protrusion.

[0014] Furthermore, the third positioning mechanism includes a second protrusion protruding upward on the left side of the bottom module, a first protrusion protruding upward on the right side of the bottom module, a second groove provided on the outer side of the lower side of the left module, and a first groove provided on the outer side of the lower side of the right module.

[0015] Furthermore, the fourth positioning mechanism includes a second protrusion protruding downward from the left side of the upper module, a first protrusion protruding downward from the right side of the upper module, a second groove provided on the outer side of the upper side of the left module, and a first groove provided on the outer side of the upper side of the right module.

[0016] Furthermore, a plurality of mutually connected convex strip groups protruding upward are provided in the middle portion of the wavy base surface on the upper surface of the bottom module, the left and right sides of the convex strip groups are inclined surfaces, and the front and rear sides of the convex strip groups are inclined wave surfaces; a downwardly protruding boss is provided on the lower side of the upper module along the circumference of the grouting port, the left and right sides of the boss are inclined surfaces, and the front and rear sides of the boss are inclined wave surfaces.

[0017] In summary, the technical solution of the utility model has the following beneficial effects:

[0018] The utility model solves the problem that the existing grouting forming mold has serious deformation on the upper side of the green body of the product solidified after grouting, fails to meet the qualified standard, and the peripheral lines of the green body of the product are not straight and have corrugated defects, which affect the appearance of the product. This scheme adopts the mold structure of the inverted green body of the product (i.e., the ceramic green body), and designs the upper surface of the bottom module into a structure of a wavy base surface + a convex strip group, which ensures that the upper side of the green body of the product does not deform and meets the qualified standard. In this scheme, the joint surface between the left module, the right module, the front module, and the rear module is designed as a bent fitting surface structure, which effectively prevents the peripheral lines of the green body of the product from being not straight and having corrugated defects, which affect the appearance of the product. After tightening the multiple cloth straps on the periphery of the mold, the sealing performance of the ceramic green body accommodating cavity after grouting is improved, ensuring that the ceramic green body has a beautiful appearance and meets the requirements in size. The first positioning mechanism, the second positioning mechanism, the third positioning mechanism, and the fourth positioning mechanism of this scheme further improve the precision and sealing performance of the product. In short, the mold design of this scheme is simple, reasonable, practical, and low-cost, which improves production efficiency and product qualification rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the embodiment of the utility model, the following is a brief introduction to the drawings required for the description of the embodiment of the utility model. Obviously, the drawings described below are only part of the embodiments of the utility model, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor.

[0020] Figure 1 A schematic diagram of a book-combined ceramic product of the utility model;

[0021] Figure 2 This is a structural diagram of a ceramic mold structure of the utility model;

[0022] Figure 3 for Figure 2 Exploded view of the ECU with the upper module removed.

[0023] Description of reference numerals:

[0024] 10-upper module, 11-grouting port, 12-boss, 20-bottom module, 21-wavy base surface, 22-convex strip group, 23-inclined surface, 24, 25-oblique wave surface, 30-left module, 31-left boss, 32-inclined chamfer, 33-first bending surface, 34-inner surface, 35-boss, 36-first protrusion, 37-second protrusion, 38-second groove, 40-right module, 41-right boss, 42-second bending surface, 43-third protrusion, 50-front module, 51-arc surface, 52-side surface, 53-third bending surface, 54-first groove, 60-rear module, 61-wavy tooth surface, 62-fourth bending surface, 70-ceramic green body accommodating cavity, 511, 611-oblique wave area. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] In order to facilitate the understanding of this scheme, Figure 2 The right figure in the figure (i.e., the figure composed of the bottom module 20, the left module 30, the right module 40, the front module 50, and the rear module 60) is for reference. The top, bottom, left, right, front, back, inside, and outside in the right figure are the top, bottom, left, right, front, back, inside, and outside in the specification. Figure 2 The left picture in the figure is a schematic diagram of the upper module 10, the top in the left picture is the bottom of the (upper module 10) in the specification, the bottom in the left picture is the top of the (upper module 10) in the specification, the front in the left picture is the back of the (upper module 10) in the specification, the back in the left picture is the front of the (upper module 10) in the specification, and the left and right in the left picture are the left and right of the (upper module 10) in the specification.

[0027] like Figures 1 to 3As shown, a ceramic mold structure includes an upper module 10, a bottom module 20, a left module 30, a right module 40, a front module 50, and a rear module 60 arranged between the upper module 10 and the bottom module 20. The lower side of the upper module 10 and the upper side of the bottom module 20 and the inner sides of the left module 30, the right module 40, the front module 50, and the rear module 60 together form a ceramic green body accommodating cavity 70. The upper surface of the bottom module 20 is a wavy base surface 21, and the lower sides of the left module 30, the right module 40, the front module 50, and the rear module 60 are respectively provided with wavy connecting surfaces matching the wavy base surface 21. The upper sides of the left module 30, the right module 40, the front module 50, and the rear module 60 are located in the same plane, and the joint surfaces between the left module 30, the right module 40, the front module 50, and the rear module 60 are bent fitting surfaces. A first positioning mechanism is provided between the front side of the front module 50 and the front sides of the left module 30 and the right module 40, a second positioning mechanism is provided between the rear side of the rear module 60 and the rear sides of the left module 30 and the right module 40, and a third positioning mechanism is provided between the left and right sides of the bottom module 20 and the lower sides of the left module 30 and the right module 40. A fourth positioning mechanism is provided between the left and right sides of the upper module 10 and the upper sides of the left module 30 and the right module 40. A grouting port 11 leading to the ceramic green body accommodating cavity 70 is provided in the middle of the upper module 10. A plurality of cloth straps (not shown in the figure, the cloth straps are evenly distributed in the upper, middle and lower areas of the mold) are used to tighten them laterally along the periphery of the left module 30, the front module 50, the right module 40 and the rear module 60. A plurality of cloth straps (the cloth straps are distributed on the left and right of the grouting port 11) are used to tighten them longitudinally along the periphery of the upper module 10, the front module 50, the bottom module 20 and the rear module 60. A plurality of cloth straps (the cloth straps are distributed on the left and right of the grouting port 11) are used to tighten them longitudinally along the periphery of the upper module 10, the left module 30, the bottom module 20 and the right module 40.

[0028] Specifically, the inner surface of the left module 30 is provided with a left boss 31, the upper and lower sides of the left boss 31 are chamfered corners 32, the bent fitting surface of the left module 30 includes a first bent surface 33 on the front and rear sides of the left boss 31 and an inner surface 34 of the left module 30 connected to the first bent surface 33, and a boss 35 is provided on the inner side of the left boss 31.

[0029] Specifically, the inner surface of the right module 40 is provided with a right boss 41, the upper and lower sides of the right boss 41 are chamfered corners 32, and the bent fitting surface of the right module 40 includes a second bent surface 42 on the front and rear sides of the right boss 41 and an inner surface 34 of the right module 40 connected to the second bent surface 42.

[0030] Specifically, the inner surface of the front module 50 is a plurality of arcuate surfaces 51 vertically connected in sequence, and the bent fitting surface of the front module 50 includes side surfaces 52 on the left and right sides of the front module 50 and a third bent surface 53 connected to the side surfaces 52 .

[0031] Specifically, the inner surface of the rear module 60 is a plurality of corrugated tooth surfaces 61 vertically connected in sequence, and the bent fitting surface of the rear module 60 includes the side surfaces 52 on the left and right sides of the rear module 60 and a fourth bent surface 62 connected to the side surfaces 52 .

[0032] Specifically, the first positioning mechanism includes a first groove 54 arranged on the left and right sides of the front module 50, a first protrusion 36 arranged on the front side of the left module 30 and protruding to the right, and a first protrusion 36 arranged on the front side of the right module 40 and protruding to the left. The first groove 54 matches the first protrusion 36.

[0033] Specifically, the second positioning mechanism includes a second groove (not shown) disposed on the left rear side of the rear module 60, a third groove (not shown) disposed on the right rear side of the rear module 60, a second convex block 37 disposed on the rear side of the left module 30 and protruding to the right, and a third convex block 43 disposed on the rear side of the right module 40 and protruding to the left, the second groove matches the second convex block 37, and the third groove matches the third convex block 43. The second positioning mechanism not only plays a positioning role, but also has a function of preventing wrong installation.

[0034] Specifically, the third positioning mechanism includes a second protrusion 37 protruding upward on the left side of the bottom module 20, a first protrusion 36 protruding upward on the right side of the bottom module 20, a second groove 38 provided on the outer side of the lower side of the left module 30, and a first groove 54 provided on the outer side of the lower side of the right module 40.

[0035] Specifically, the fourth positioning mechanism includes a second protrusion 37 protruding downward on the left side of the upper module 10, a first protrusion 36 protruding downward on the right side of the upper module 10, a second groove 38 provided on the outer upper side of the left module 30, and a first groove 54 provided on the outer upper side of the right module 40.

[0036] Specifically, a plurality of mutually connected convex strip groups 22 are provided in the middle of the wavy base surface 21 on the upper surface of the bottom module 20, and the left and right sides of the convex strip group 22 are inclined surfaces 23, and the inclined surfaces 23 match the inclined chamfers 32 on the lower sides of the left boss 31 and the right boss 41. The front and rear sides of the convex strip group 22 are oblique wave surfaces 24 and 25, and the oblique wave surfaces 24 and 25 match the oblique wave areas 511 and 611 on the lower sides of the arc surface 51 and the wave tooth surface 61, respectively. The upper surface of the convex strip group 22 is provided with a wave tooth surface 61.

[0037] A downwardly protruding boss 12 is provided on the lower side of the upper module 10 along the circumference of the grouting port 11, the left and right sides of the boss 12 are inclined surfaces 23, and the front and rear sides of the boss 12 are oblique wave surfaces 24 and 25, which respectively match the oblique wave areas 511 and 611 on the upper sides of the arc surface 51 and the corrugated tooth surface 61.

[0038] Preferably, the upper module 10, the bottom module 20, the left module 30, the right module 40, the front module 50, and the rear module 60 are all made of gypsum. In this solution, the slurry water injected from the grouting port 11 is a mixture of mud and water. After the injection is completed and dried, the cloth band is loosened, and the upper module 10, the left module 30, the right module 40, the front module 50, and the rear module 60 are removed, and the inverted ceramic green body can be taken out from the bottom module 20 (see Figure 1 The ceramic green body is then placed in a kiln and fired into a ceramic product, such as Figure 1 .

[0039] The wavy connecting surfaces on the lower sides of the left module 30, the right module 40, the front module 50 and the rear module 60 of the present invention match the wavy base surface 21, and the bent fitting surfaces between the left module 30, the right module 40, the front module 50 and the rear module 60, after being tightened with the cloth straps, ensure the overall sealing of the ceramic green body accommodating cavity 70 due to the good density and high temperature resistance of the gypsum material, and the smooth and flat surface treatment of the wavy connecting surfaces and the bent fitting surfaces, thereby overcoming the defects of the existing grouting molding molds and improving the qualification rate of ceramic green bodies and ceramic products.

[0040] The ceramic product of this scheme is a book combination. The convex strip group 22 on the bottom module 20 forms the (uneven) upper side of the book combination and depicts the outline of the upper pages and cover of each book. The corrugated tooth surface 61 of the rear module 60 forms the front side of the book combination and depicts the outline of the front pages and cover of each book. The arc surface 51 of the front module 50 forms the back side of the book combination and depicts the outline of the cover of each book. The left boss 31 and the boss 35 of the left module 30 form the left side of the book combination and depict the outline of the cover of the left book. The inventive principle of this scheme is not only used for the grouting mold of the book combination ceramic product, but also can be used for the production of grouting molds for other uneven or irregularly shaped ceramic products. They are not listed here one by one.

[0041] In summary, the technical solution of the utility model has the following beneficial effects:

[0042] The utility model solves the problem that the existing grouting forming mold has serious deformation on the upper side of the green body of the product solidified after grouting, fails to meet the qualified standard, and the lines on the circumference of the green body of the product are not straight and have corrugated defects, which affects the appearance of the product. This scheme adopts the mold structure of the inverted green body of the product (i.e., the ceramic green body), and designs the upper surface of the bottom module into a structure of a wavy base surface + a convex strip group, which ensures that the upper side of the green body of the product does not deform and meets the qualified standard. In this scheme, the joint surface between the left module, the right module, the front module, and the rear module is designed as a bent fitting surface structure, which effectively prevents the lines on the circumference of the green body of the product from being not straight and having corrugated defects, which affects the appearance of the product. After tightening the multiple cloth straps on the periphery of the mold, the sealing performance of the ceramic green body accommodating cavity after grouting is improved, ensuring that the ceramic green body has a beautiful appearance and meets the requirements in size. The first positioning mechanism, the second positioning mechanism, the third positioning mechanism, and the fourth positioning mechanism of this scheme further improve the precision and sealing performance of the product. In short, the mold design of this scheme is simple, reasonable, practical, and low-cost, which improves production efficiency and product qualification rate.

[0043] The above-described implementation methods do not constitute a limitation on the protection scope of the technical solution. Any modification, equivalent replacement and improvement made within the spirit and principle of the above-described implementation methods shall be included in the protection scope of the technical solution.

Claims

1. A ceramic mold structure, characterized in that: The invention comprises an upper module, a bottom module, a left module, a right module, a front module and a rear module arranged between the upper module and the bottom module, the lower side of the upper module and the upper side of the bottom module and the inner sides of the left module, the right module, the front module and the rear module jointly form a ceramic green body accommodating cavity; the upper surface of the bottom module is a wavy base surface, the lower sides of the left module, the right module, the front module and the rear module are respectively provided with wavy connecting surfaces matching the wavy base surface, the upper sides of the left module, the right module, the front module and the rear module are located in the same plane, the joint surfaces between the left module, the right module, the front module and the rear module are bent fitting surfaces, and a front side is provided between the front side of the front module and the front sides of the left module and the right module There is a first positioning mechanism, a second positioning mechanism is provided between the rear side of the rear module and the rear sides of the left module and the right module, a third positioning mechanism is provided between the left and right sides of the bottom module and the lower sides of the left module and the right module, a fourth positioning mechanism is provided between the left and right sides of the upper module and the upper sides of the left module and the right module, a grouting port leading to the ceramic green body accommodating cavity is provided in the middle of the upper module, a plurality of cloth straps are used to tighten horizontally along the periphery of the left module, the front module, the right module and the rear module, a plurality of cloth straps are used to tighten longitudinally along the periphery of the upper module, the front module, the bottom module and the rear module, and a plurality of cloth straps are used to tighten longitudinally along the periphery of the upper module, the left module, the bottom module and the right module.

2. A ceramic mold structure according to claim 1, characterized in that: The inner surface of the left module is provided with a left boss, the upper and lower sides of the left boss are chamfered, the bent fitting surface of the left module includes a first bending surface on the front and rear sides of the left boss and the inner surface of the left module connected to the first bending surface, and a convex column is provided on the inner side of the left boss.

3. A ceramic mold structure according to claim 2, characterized in that: The inner surface of the right module is provided with a right boss, the upper and lower sides of the right boss are chamfered, and the bent fitting surface of the right module includes a second bent surface on the front and rear sides of the right boss and the inner surface of the right module connected to the second bent surface.

4. A ceramic mold structure according to claim 3, characterized in that: The inner surface of the front module is a plurality of arc-shaped surfaces connected in sequence vertically, and the bent fitting surface of the front module includes side surfaces on the left and right sides of the front module and a third bent surface connected to the side surfaces.

5. A ceramic mold structure according to claim 4, characterized in that: The inner surface of the rear module is a plurality of corrugated tooth surfaces connected in sequence vertically, and the bent fitting surface of the rear module includes side surfaces on the left and right sides of the rear module and a fourth bent surface connected to the side surfaces.

6. A ceramic mold structure according to claim 5, characterized in that: The first positioning mechanism includes a first groove arranged on the left and right sides of the front side of the front module, a first bump arranged on the front side of the left module and protruding to the right, and a first bump arranged on the front side of the right module and protruding to the left, and the first groove matches the first bump.

7. A ceramic mold structure according to claim 6, characterized in that: The second positioning mechanism includes a second groove arranged on the left rear side of the rear module, a third groove arranged on the right rear side of the rear module, a second protrusion arranged on the rear side of the left module and protruding to the right, and a third protrusion arranged on the rear side of the right module and protruding to the left. The second groove matches the second protrusion, and the third groove matches the third protrusion.

8. A ceramic mold structure according to claim 7, characterized in that: The third positioning mechanism includes a second protrusion protruding upwardly on the left side of the bottom module, a first protrusion protruding upwardly on the right side of the bottom module, a second groove provided on the outer side of the lower side of the left module, and a first groove provided on the outer side of the lower side of the right module.

9. A ceramic mold structure according to claim 8, characterized in that: The fourth positioning mechanism includes a second protrusion protruding downwardly on the left side of the upper module, a first protrusion protruding downwardly on the right side of the upper module, a second groove provided on the outer side of the upper side of the left module, and a first groove provided on the outer side of the upper side of the right module.

10. A ceramic mold structure according to claim 9, characterized in that: A plurality of mutually connected convex strip groups protruding upward are provided in the middle of the wavy base surface on the upper surface of the bottom module, the left and right sides of the convex strip groups are inclined surfaces, and the front and rear sides of the convex strip groups are inclined wave surfaces; a downwardly protruding boss is provided on the lower side of the upper module along the circumference of the grouting port, the left and right sides of the boss are inclined surfaces, and the front and rear sides of the boss are inclined wave surfaces.