# US 2009/0266643 A1 · Silencer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2009/0266643 A1 - Document ID: US20090266643A1 - Status: Published application - Kind: A1 - Application number: 11/813,277 - Filed: 2006-01-12 - Published: 2009-10-29 - Earliest claimed: 2005-01-13 - Assignees: SMC Corporation - Inventors: Yoshihiro Fukano; Shoichi Makado - Web page: https://patentgrep.com/patent/US20090266643A1 ## CPC - F04B 39/0055: {with a special shape of fluid passage, e.g. bends, throttles, diameter changes, pipes} - F04B 39/0033: {with encapsulations} - F04B 39/0038: {of inlet or outlet channels} - F15B 21/008: {Reduction of noise or vibration} - F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F) - F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR ## Abstract A silencer includes a cylindrical member held between a body connected to an exhaust side of a fluid pressure device and a disk-shaped retaining member. A net-shaped sound absorber is disposed around an outer circumference of the cylindrical member. A pressure fluid flows from the body into the interior of the cylindrical member and is discharged toward the sound absorber through a plurality of first through fifth exhaust holes formed in the cylindrical member. Accordingly, dust in the pressure fluid is removed by the sound absorber, which is formed of a plurality of stacked filters, and further, the pressure fluid is discharged to the outside after exhaust noises have been absorbed by the sound absorber. ## Claims ### Claim 1 A silencer for causing a reduction in exhaust noises of a pressure fluid exhausted from a fluid pressure device, comprising: a main body portion to which said fluid pressure device is connected and to which a pressure fluid from said fluid pressure device is introduced; a sound absorber retained within said main body portion and formed from filters made up of plural stacked layers having different opening areas; and a flow adjustment mechanism for gradually increasing a flow amount of the pressure fluid exhausted to the outside from said main body portion through said sound absorber in a direction separating away from said fluid pressure device, wherein the opening areas of said filters are set so as to become gradually smaller directed from an upstream side formed at a side of said main body portion toward a downstream side formed at an exterior side of said sound absorber. ### Claim 2 (depends on 1) The silencer according to claim 1, wherein said flow adjustment mechanism preferably includes a fluid passage for enabling a pressure fluid to flow from said main body portion to the exterior of said sound absorber, and wherein a passage area of said fluid passage is formed so as to become gradually larger in a direction separating away from said fluid pressure device. ### Claim 3 (depends on 2) The silencer according to claim 2, wherein said fluid passage is formed from a cylindrical body disposed inside said sound absorber and communicating with said main body portion, having a plurality of exhaust holes that become gradually greater in quantity in a direction separating away from the fluid pressure device. ### Claim 4 (depends on 3) The silencer according to claim 3, wherein a clearance is disposed between said cylindrical body and said sound absorber. ### Claim 5 (depends on 4) The silencer according to claim 4, wherein said filters are constructed from three layers, which are stacked radially. ### Claim 6 (depends on 5) The silencer according to claim 5, wherein said filters have respective thickness dimensions in the radial direction that are substantially uniform. ### Claim 7 (depends on 6) The silencer according to claim 6, wherein a cylindrical cover member surrounding said sound absorber is connected to said main body portion, wherein said cover member has holes therein through which said pressure fluid that flows through the sound absorber also flows. ### Claim 8 (depends on 2) The silencer according to claim 2, wherein said flow adjustment mechanism comprises filters having thickness dimensions becoming gradually smaller in a direction separating away from said fluid pressure device. ### Claim 9 (depends on 1) The silencer according to claim 1, wherein a detection mechanism is disposed in said main body portion for detecting a case in which the pressure of said pressure fluid inside said main body portion rises to a predetermined value or above. ### Claim 10 (depends on 9) The silencer according to claim 9, wherein said detection mechanism comprises: a communication passage disposed in said main body portion communicating the interior of the main body portion with the outside; a valve seated on a valve seat formed in said communication passage; and a spring for pressing said valve toward said valve seat.